Collapse apex-pdp maven model submodules

This review collapses all the code in six podel submodules into a single
model module. There are no code changes, just files moved around.

This change reduces the complexity of the code structure and speeds up
the build.

Issue-ID: POLICY-1820
Change-Id: Ifb644e8ec85ae6d0987378f4616fbc8a8858a9a8
Signed-off-by: liamfallon <liam.fallon@est.tech>

76 files changed, 11780 insertions, 0 deletions

diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxConceptGetterImplTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxConceptGetterImplTest.java
new file mode 100644
index 000000000..44a9de49e
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxConceptGetterImplTest.java
@@ -0,0 +1,84 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import java.util.NavigableMap;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import org.junit.Test;
+
+/**
+ * Test the AxConceptGetterImpl class.
+ */
+public class AxConceptGetterImplTest {
+
+    @Test
+    public void testAxConceptGetterImpl() {
+        NavigableMap<AxArtifactKey, AxArtifactKey> keyMap = new TreeMap<>();
+
+        AxConceptGetterImpl<AxArtifactKey> getter = new AxConceptGetterImpl<>(keyMap);
+        assertNotNull(getter);
+
+        AxArtifactKey keyA = new AxArtifactKey("A", "0.0.1");
+        assertNull(getter.get(keyA));
+
+        assertThatThrownBy(() -> getter.get((String) null))
+            .hasMessage("conceptKeyName may not be null");
+        assertNull(getter.get("W"));
+
+        AxArtifactKey keyZ = new AxArtifactKey("Z", "0.0.1");
+        keyMap.put(keyZ, keyZ);
+        assertNull(getter.get("W"));
+
+        AxArtifactKey keyW001 = new AxArtifactKey("W", "0.0.1");
+        keyMap.put(keyW001, keyW001);
+        assertEquals(keyW001, getter.get("W"));
+
+        AxArtifactKey keyW002 = new AxArtifactKey("W", "0.0.2");
+        keyMap.put(keyW002, keyW002);
+        assertEquals(keyW002, getter.get("W"));
+
+        keyMap.remove(keyZ);
+        assertEquals(keyW002, getter.get("W"));
+
+        assertThatThrownBy(() -> getter.get((String) null, "0.0.1"))
+            .hasMessage("conceptKeyName may not be null");
+        assertEquals(keyW002, getter.get("W", "0.0.2"));
+        assertEquals(keyW002, getter.get("W", (String) null));
+
+        assertEquals(new TreeSet<AxArtifactKey>(keyMap.values()), getter.getAll(null));
+        assertEquals(new TreeSet<AxArtifactKey>(keyMap.values()), getter.getAll(null, null));
+
+        assertEquals(keyW001, getter.getAll("W", null).iterator().next());
+        assertEquals(keyW002, getter.getAll("W", "0.0.2").iterator().next());
+        assertEquals(0, getter.getAll("A", null).size());
+        assertEquals(0, getter.getAll("Z", null).size());
+
+        keyMap.put(keyZ, keyZ);
+        assertEquals(keyW002, getter.getAll("W", "0.0.2").iterator().next());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyInfoTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyInfoTest.java
new file mode 100644
index 000000000..0c7edee28
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyInfoTest.java
@@ -0,0 +1,108 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.util.UUID;
+import org.junit.Test;
+
+
+public class AxKeyInfoTest {
+
+    @Test
+    public void testNullAxKeyInfo() {
+        assertNotNull(new AxKeyInfo());
+        assertNotNull(new AxKeyInfo(new AxArtifactKey()));
+        assertNotNull(new AxKeyInfo(new AxArtifactKey(), UUID.randomUUID(), "Key description"));
+    }
+
+    @Test
+    public void testAxKeyInfo() {
+        AxKeyInfo testKeyInfo = new AxKeyInfo();
+        testKeyInfo.setKey((new AxArtifactKey("PN", "0.0.1")));
+        assertEquals("PN:0.0.1", testKeyInfo.getKey().getId());
+        assertTrue(testKeyInfo.matchesId("PN:0.0.1"));
+
+        AxArtifactKey key = new AxArtifactKey("key", "0.0.1");
+        testKeyInfo.setKey(key);
+        assertEquals(key, testKeyInfo.getKey());
+
+        UUID uuid = UUID.randomUUID();
+        testKeyInfo.setUuid(uuid);
+        assertEquals(uuid, testKeyInfo.getUuid());
+        testKeyInfo.setDescription("Key Description");
+        assertEquals("Key Description", testKeyInfo.getDescription());
+
+        AxKeyInfo clonedReferenceKey = new AxKeyInfo(testKeyInfo);
+        assertTrue(clonedReferenceKey.toString()
+                        .startsWith("AxKeyInfo:(artifactId=AxArtifactKey:(name=key,version=0.0.1),uuid="));
+
+        assertNotEquals(0, testKeyInfo.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(testKeyInfo, testKeyInfo); // NOSONAR
+        assertEquals(testKeyInfo, clonedReferenceKey);
+        assertNotNull(testKeyInfo);
+        Object differentKeyType = new AxArtifactKey();
+        assertNotEquals(testKeyInfo, differentKeyType);
+        assertNotEquals(testKeyInfo, new AxKeyInfo(new AxArtifactKey()));
+        assertNotEquals(testKeyInfo, new AxKeyInfo(key, UUID.randomUUID(), "Some Description"));
+        assertEquals(testKeyInfo, new AxKeyInfo(key, uuid, "Some Other Description"));
+        assertEquals(testKeyInfo, new AxKeyInfo(key, uuid, "Key Description"));
+
+        assertEquals(0, testKeyInfo.compareTo(testKeyInfo));
+        assertEquals(0, testKeyInfo.compareTo(clonedReferenceKey));
+
+
+    }
+
+    @Test
+    public void testAxKeyValidation() {
+        AxKeyInfo testKeyInfo = new AxKeyInfo();
+        testKeyInfo.setKey((new AxArtifactKey("PN", "0.0.1")));
+
+        AxValidationResult result = new AxValidationResult();
+        result = testKeyInfo.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        testKeyInfo.setDescription("");
+        result = testKeyInfo.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.OBSERVATION, result.getValidationResult());
+
+        testKeyInfo.setUuid(new UUID(0, 0));
+        result = testKeyInfo.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.WARNING, result.getValidationResult());
+
+        testKeyInfo.setKey(AxArtifactKey.getNullKey());
+        result = testKeyInfo.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.INVALID, result.getValidationResult());
+
+        assertNotNull(AxKeyInfo.generateReproducibleUuid(null));
+        assertNotNull(AxKeyInfo.generateReproducibleUuid("SeedString"));
+
+        testKeyInfo.clean();
+        assertNotNull(testKeyInfo);
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyTest.java
new file mode 100644
index 000000000..010f4b8a3
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyTest.java
@@ -0,0 +1,189 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.lang.reflect.Field;
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey.Compatibility;
+
+public class AxKeyTest {
+
+    private static AxArtifactKey someKey0;
+    private static AxArtifactKey someKey1;
+    private static AxArtifactKey someKey2;
+    private static AxArtifactKey someKey3;
+    private static AxArtifactKey someKey4;
+    private static AxArtifactKey someKey5;
+    private static AxArtifactKey someKey6;
+
+    /**
+     * Sets data in Keys for the tests.
+     */
+    @Before
+    public void setKeys() {
+        someKey0 = new AxArtifactKey();
+        someKey1 = new AxArtifactKey("name", "0.0.1");
+        someKey2 = new AxArtifactKey(someKey1);
+        someKey3 = new AxArtifactKey(someKey1.getId());
+        someKey4 = new AxArtifactKey(someKey1);
+        someKey5 = new AxArtifactKey(someKey1);
+        someKey6 = new AxArtifactKey(someKey1);
+    }
+
+    private void setKeyValues() {
+        someKey0.setName("zero");
+        someKey0.setVersion("0.0.2");
+        someKey3.setVersion("0.0.2");
+        someKey4.setVersion("0.1.2");
+        someKey5.setVersion("1.2.2");
+        someKey6.setVersion("3");
+    }
+
+    @Test
+    public void testArtifactKey() {
+        assertThatThrownBy(() -> new AxArtifactKey("some bad key id"))
+            .hasMessage("parameter \"id\": value \"some bad key id\", "
+                            + "does not match regular expression \"[A-Za-z0-9\\-_\\.]+:[0-9].[0-9].[0-9]\"");
+
+        assertEquals(AxArtifactKey.getNullKey(), someKey0);
+
+        assertEquals(someKey1, someKey2);
+        assertEquals(someKey1, someKey3);
+
+        assertEquals(someKey2, someKey1.getKey());
+        assertEquals(1, someKey1.getKeys().size());
+
+        setKeyValues();
+
+        someKey0.clean();
+        assertNotNull(someKey0.toString());
+
+        AxArtifactKey someKey7 = new AxArtifactKey(someKey1);
+        assertEquals(150332875, someKey7.hashCode());
+        assertEquals(0, someKey7.compareTo(someKey1));
+        assertEquals(-12, someKey7.compareTo(someKey0));
+
+        assertThatThrownBy(() -> someKey0.compareTo(null))
+            .hasMessage("comparison object may not be null");
+        assertEquals(0, someKey0.compareTo(someKey0));
+        assertEquals(353602977, someKey0.compareTo(new AxReferenceKey()));
+
+        assertNotNull(someKey0);
+        // disabling sonar because this code tests the equals() method
+        assertEquals(someKey0, someKey0); // NOSONAR
+        assertNotEquals(someKey0, (Object) new AxReferenceKey());
+    }
+
+    @Test
+    public void testAxCompatibility() {
+        setKeyValues();
+
+        assertEquals(Compatibility.DIFFERENT, someKey0.getCompatibility(new AxReferenceKey()));
+        assertEquals(Compatibility.DIFFERENT, someKey0.getCompatibility(someKey1));
+        assertEquals(Compatibility.IDENTICAL, someKey2.getCompatibility(someKey1));
+        assertEquals(Compatibility.PATCH, someKey3.getCompatibility(someKey1));
+        assertEquals(Compatibility.MINOR, someKey4.getCompatibility(someKey1));
+        assertEquals(Compatibility.MAJOR, someKey5.getCompatibility(someKey1));
+        assertEquals(Compatibility.MAJOR, someKey6.getCompatibility(someKey1));
+
+        assertTrue(someKey1.isCompatible(someKey2));
+        assertTrue(someKey1.isCompatible(someKey3));
+        assertTrue(someKey1.isCompatible(someKey4));
+        assertFalse(someKey1.isCompatible(someKey0));
+        assertFalse(someKey1.isCompatible(someKey5));
+        assertFalse(someKey1.isCompatible(new AxReferenceKey()));
+    }
+
+    @Test
+    public void testAxValidation() {
+        setKeyValues();
+
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey0.validate(new AxValidationResult()).getValidationResult());
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey1.validate(new AxValidationResult()).getValidationResult());
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey2.validate(new AxValidationResult()).getValidationResult());
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey3.validate(new AxValidationResult()).getValidationResult());
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey4.validate(new AxValidationResult()).getValidationResult());
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey5.validate(new AxValidationResult()).getValidationResult());
+        assertEquals(AxValidationResult.ValidationResult.VALID,
+                        someKey6.validate(new AxValidationResult()).getValidationResult());
+    }
+
+    @Test
+    public void testNullKey() {
+        setKeyValues();
+
+        AxArtifactKey nullKey0 = AxArtifactKey.getNullKey();
+        assertTrue(nullKey0.isNullKey());
+        AxArtifactKey nullKey1 = new AxArtifactKey();
+        assertTrue(nullKey1.isNullKey());
+        AxArtifactKey nullKey2 = new AxArtifactKey(AxKey.NULL_KEY_NAME, AxKey.NULL_KEY_VERSION);
+        assertTrue(nullKey2.isNullKey());
+        AxArtifactKey notnullKey = new AxArtifactKey("Blah", AxKey.NULL_KEY_VERSION);
+        assertFalse(notnullKey.isNullKey());
+    }
+
+
+    @Test
+    public void testValidation() throws IllegalArgumentException, IllegalAccessException,
+        NoSuchFieldException, SecurityException {
+        AxArtifactKey testKey = new AxArtifactKey("TheKey", "0.0.1");
+        assertEquals("TheKey:0.0.1", testKey.getId());
+
+        Field nameField = testKey.getClass().getDeclaredField("name");
+        nameField.setAccessible(true);
+        nameField.set(testKey, "Key Name");
+        AxValidationResult validationResult = new AxValidationResult();
+        testKey.validate(validationResult);
+        nameField.set(testKey, "TheKey");
+        nameField.setAccessible(false);
+        assertEquals(
+            "name invalid-parameter name with value Key Name "
+                + "does not match regular expression [A-Za-z0-9\\-_\\.]+",
+            validationResult.getMessageList().get(0).getMessage());
+
+        Field versionField = testKey.getClass().getDeclaredField("version");
+        versionField.setAccessible(true);
+        versionField.set(testKey, "Key Version");
+        AxValidationResult validationResultV = new AxValidationResult();
+        testKey.validate(validationResultV);
+        versionField.set(testKey, "0.0.1");
+        versionField.setAccessible(false);
+        assertEquals(
+            "version invalid-parameter version with value Key Version "
+                + "does not match regular expression [A-Za-z0-9.]+",
+            validationResultV.getMessageList().get(0).getMessage());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyUseTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyUseTest.java
new file mode 100644
index 000000000..5346b6b21
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxKeyUseTest.java
@@ -0,0 +1,78 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey.Compatibility;
+
+public class AxKeyUseTest {
+
+    @Test
+    public void test() {
+        assertNotNull(new AxKeyUse());
+        assertNotNull(new AxKeyUse(new AxArtifactKey()));
+        assertNotNull(new AxKeyUse(new AxReferenceKey()));
+
+        AxArtifactKey key = new AxArtifactKey("Key", "0.0.1");
+        AxKeyUse keyUse = new AxKeyUse();
+        keyUse.setKey(key);
+        assertEquals(key, keyUse.getKey());
+        assertEquals("Key:0.0.1", keyUse.getId());
+        assertEquals(key, keyUse.getKeys().get(0));
+
+        assertEquals(Compatibility.IDENTICAL, keyUse.getCompatibility(key));
+        assertTrue(keyUse.isCompatible(key));
+
+        keyUse.clean();
+        assertNotNull(keyUse);
+
+        AxValidationResult result = new AxValidationResult();
+        result = keyUse.validate(result);
+        assertNotNull(result);
+
+        assertNotEquals(0, keyUse.hashCode());
+
+        AxKeyUse clonedKeyUse = new AxKeyUse(keyUse);
+        assertEquals("AxKeyUse:(usedKey=AxArtifactKey:(name=Key,version=0.0.1))", clonedKeyUse.toString());
+
+        assertNotEquals(0, keyUse.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(keyUse, keyUse); // NOSONAR
+        assertEquals(keyUse, clonedKeyUse);
+        assertNotEquals(keyUse, (Object) "Hello");
+        assertEquals(keyUse, new AxKeyUse(key));
+
+        assertEquals(0, keyUse.compareTo(keyUse));
+        assertEquals(0, keyUse.compareTo(clonedKeyUse));
+        assertNotEquals(0, keyUse.compareTo(new AxArtifactKey()));
+        assertEquals(0, keyUse.compareTo(new AxKeyUse(key)));
+
+        AxKeyUse keyUseNull = new AxKeyUse(AxArtifactKey.getNullKey());
+        AxValidationResult resultNull = new AxValidationResult();
+        assertEquals(false, keyUseNull.validate(resultNull).isValid());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxReferenceKeyTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxReferenceKeyTest.java
new file mode 100644
index 000000000..515587558
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/AxReferenceKeyTest.java
@@ -0,0 +1,177 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.lang.reflect.Field;
+import org.junit.Test;
+
+
+public class AxReferenceKeyTest {
+
+    @Test
+    public void testAxReferenceKey() {
+        assertNotNull(new AxReferenceKey());
+        assertNotNull(new AxReferenceKey(new AxArtifactKey()));
+        assertNotNull(new AxReferenceKey(new AxArtifactKey(), "LocalName"));
+        assertNotNull(new AxReferenceKey(new AxReferenceKey()));
+        assertNotNull(new AxReferenceKey(new AxReferenceKey(), "LocalName"));
+        assertNotNull(new AxReferenceKey(new AxArtifactKey(), "ParentLocalName", "LocalName"));
+        assertNotNull(new AxReferenceKey("ParentKeyName", "0.0.1", "LocalName"));
+        assertNotNull(new AxReferenceKey("ParentKeyName", "0.0.1", "ParentLocalName", "LocalName"));
+        assertNotNull(new AxReferenceKey("ParentKeyName:0.0.1:ParentLocalName:LocalName"));
+        assertEquals(AxReferenceKey.getNullKey().getKey(), AxReferenceKey.getNullKey());
+        assertEquals("NULL:0.0.0:NULL:NULL", AxReferenceKey.getNullKey().getId());
+
+        AxReferenceKey testReferenceKey = new AxReferenceKey();
+        testReferenceKey.setParentArtifactKey(new AxArtifactKey("PN", "0.0.1"));
+        assertEquals("PN:0.0.1", testReferenceKey.getParentArtifactKey().getId());
+
+        testReferenceKey.setParentReferenceKey(new AxReferenceKey("PN", "0.0.1", "LN"));
+        assertEquals("PN:0.0.1:NULL:LN", testReferenceKey.getParentReferenceKey().getId());
+
+        testReferenceKey.setParentKeyName("NPKN");
+        assertEquals("NPKN", testReferenceKey.getParentKeyName());
+
+        testReferenceKey.setParentKeyVersion("0.0.1");
+        assertEquals("0.0.1", testReferenceKey.getParentKeyVersion());
+
+        testReferenceKey.setParentLocalName("NPKLN");
+        assertEquals("NPKLN", testReferenceKey.getParentLocalName());
+
+        testReferenceKey.setLocalName("NLN");
+        assertEquals("NLN", testReferenceKey.getLocalName());
+
+        assertFalse(testReferenceKey.isCompatible(AxArtifactKey.getNullKey()));
+        assertFalse(testReferenceKey.isCompatible(AxReferenceKey.getNullKey()));
+        assertTrue(testReferenceKey.isCompatible(testReferenceKey));
+
+        assertEquals(AxKey.Compatibility.DIFFERENT, testReferenceKey.getCompatibility(AxArtifactKey.getNullKey()));
+        assertEquals(AxKey.Compatibility.DIFFERENT, testReferenceKey.getCompatibility(AxReferenceKey.getNullKey()));
+        assertEquals(AxKey.Compatibility.IDENTICAL, testReferenceKey.getCompatibility(testReferenceKey));
+
+        AxValidationResult result = new AxValidationResult();
+        result = testReferenceKey.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        testReferenceKey.clean();
+
+        AxReferenceKey clonedReferenceKey = new AxReferenceKey(testReferenceKey);
+        assertEquals("AxReferenceKey:(parentKeyName=NPKN,parentKeyVersion=0.0.1,parentLocalName=NPKLN,localName=NLN)",
+            clonedReferenceKey.toString());
+
+        assertNotEquals(0, testReferenceKey.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(testReferenceKey, testReferenceKey); // NOSONAR
+        assertEquals(testReferenceKey, clonedReferenceKey);
+        assertNotEquals(testReferenceKey, (Object) "Hello");
+        assertNotEquals(testReferenceKey, new AxReferenceKey("PKN", "0.0.2", "PLN", "LN"));
+        assertNotEquals(testReferenceKey, new AxReferenceKey("NPKN", "0.0.2", "PLN", "LN"));
+        assertNotEquals(testReferenceKey, new AxReferenceKey("NPKN", "0.0.1", "PLN", "LN"));
+        assertNotEquals(testReferenceKey, new AxReferenceKey("NPKN", "0.0.1", "NPLN", "LN"));
+        assertEquals(testReferenceKey, new AxReferenceKey("NPKN", "0.0.1", "NPKLN", "NLN"));
+
+        assertEquals(0, testReferenceKey.compareTo(testReferenceKey));
+        assertEquals(0, testReferenceKey.compareTo(clonedReferenceKey));
+        assertNotEquals(0, testReferenceKey.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, testReferenceKey.compareTo(new AxReferenceKey("PKN", "0.0.2", "PLN", "LN")));
+        assertNotEquals(0, testReferenceKey.compareTo(new AxReferenceKey("NPKN", "0.0.2", "PLN", "LN")));
+        assertNotEquals(0, testReferenceKey.compareTo(new AxReferenceKey("NPKN", "0.0.1", "PLN", "LN")));
+        assertNotEquals(0, testReferenceKey.compareTo(new AxReferenceKey("NPKN", "0.0.1", "NPLN", "LN")));
+        assertEquals(0, testReferenceKey.compareTo(new AxReferenceKey("NPKN", "0.0.1", "NPKLN", "NLN")));
+
+        assertNotNull(testReferenceKey.getKeys());
+
+        assertThatThrownBy(() -> testReferenceKey.equals(null))
+            .hasMessage("comparison object may not be null");
+        assertThatThrownBy(() -> testReferenceKey.copyTo(null))
+            .hasMessage("target may not be null");
+        assertThatThrownBy(() -> testReferenceKey.copyTo(new AxArtifactKey("Key", "0.0.1")))
+            .hasMessage("org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey is not an instance of "
+                + "org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey");
+        AxReferenceKey targetRefKey = new AxReferenceKey();
+        assertEquals(testReferenceKey, testReferenceKey.copyTo(targetRefKey));
+    }
+
+    @Test
+    public void testValidation() throws IllegalArgumentException, IllegalAccessException,
+        NoSuchFieldException, SecurityException {
+        AxReferenceKey testReferenceKey = new AxReferenceKey();
+        testReferenceKey.setParentArtifactKey(new AxArtifactKey("PN", "0.0.1"));
+        assertEquals("PN:0.0.1", testReferenceKey.getParentArtifactKey().getId());
+
+        Field parentNameField = testReferenceKey.getClass().getDeclaredField("parentKeyName");
+        parentNameField.setAccessible(true);
+        parentNameField.set(testReferenceKey, "Parent Name");
+        AxValidationResult validationResult = new AxValidationResult();
+        testReferenceKey.validate(validationResult);
+        parentNameField.set(testReferenceKey, "ParentName");
+        parentNameField.setAccessible(false);
+        assertEquals(
+            "parentKeyName invalid-parameter parentKeyName with value Parent Name "
+                + "does not match regular expression [A-Za-z0-9\\-_\\.]+",
+            validationResult.getMessageList().get(0).getMessage());
+
+        Field parentVersionField = testReferenceKey.getClass().getDeclaredField("parentKeyVersion");
+        parentVersionField.setAccessible(true);
+        parentVersionField.set(testReferenceKey, "Parent Version");
+        AxValidationResult validationResultPV = new AxValidationResult();
+        testReferenceKey.validate(validationResultPV);
+        parentVersionField.set(testReferenceKey, "0.0.1");
+        parentVersionField.setAccessible(false);
+        assertEquals(
+            "parentKeyVersion invalid-parameter parentKeyVersion with value Parent Version "
+                + "does not match regular expression [A-Za-z0-9.]+",
+            validationResultPV.getMessageList().get(0).getMessage());
+
+        Field parentLocalNameField = testReferenceKey.getClass().getDeclaredField("parentLocalName");
+        parentLocalNameField.setAccessible(true);
+        parentLocalNameField.set(testReferenceKey, "Parent Local Name");
+        AxValidationResult validationResultPL = new AxValidationResult();
+        testReferenceKey.validate(validationResultPL);
+        parentLocalNameField.set(testReferenceKey, "ParentLocalName");
+        parentLocalNameField.setAccessible(false);
+        assertEquals(
+            "parentLocalName invalid-parameter parentLocalName with value "
+                + "Parent Local Name does not match regular expression [A-Za-z0-9\\-_\\.]+|^$",
+            validationResultPL.getMessageList().get(0).getMessage());
+
+        Field localNameField = testReferenceKey.getClass().getDeclaredField("localName");
+        localNameField.setAccessible(true);
+        localNameField.set(testReferenceKey, "Local Name");
+        AxValidationResult validationResultLN = new AxValidationResult();
+        testReferenceKey.validate(validationResultLN);
+        localNameField.set(testReferenceKey, "LocalName");
+        localNameField.setAccessible(false);
+        assertEquals(
+            "localName invalid-parameter localName with value Local Name "
+                + "does not match regular expression [A-Za-z0-9\\-_\\.]+|^$",
+            validationResultLN.getMessageList().get(0).getMessage());
+
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/DummyEntity.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/DummyEntity.java
new file mode 100644
index 000000000..2b16e89ed
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/DummyEntity.java
@@ -0,0 +1,164 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class DummyEntity extends AxConcept {
+    private static final long serialVersionUID = -2962570563281067894L;
+
+    protected AxReferenceKey key;
+    private double doubleValue;
+
+    public DummyEntity() {
+        this.key = new AxReferenceKey();
+        this.doubleValue = 0;
+    }
+
+    public DummyEntity(Double doubleValue) {
+        this.key = new AxReferenceKey();
+        this.doubleValue = doubleValue;
+    }
+
+    public DummyEntity(AxReferenceKey key, Double doubleValue) {
+        this.key = key;
+        this.doubleValue = doubleValue;
+    }
+
+    @Override
+    public AxReferenceKey getKey() {
+        return key;
+    }
+
+    @Override
+    public List<AxKey> getKeys() {
+        return Arrays.asList((AxKey) getKey());
+    }
+
+    public void setKey(AxReferenceKey key) {
+        this.key = key;
+    }
+
+    public boolean checkSetKey() {
+        return (this.key != null);
+    }
+
+    public double getDoubleValue() {
+        return doubleValue;
+    }
+
+    public void setDoubleValue(double doubleValue) {
+        this.doubleValue = doubleValue;
+    }
+
+    @Override
+    public AxValidationResult validate(AxValidationResult result) {
+        return key.validate(result);
+    }
+
+    @Override
+    public void clean() {
+        key.clean();
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("doubleValue=");
+        builder.append(doubleValue);
+        return builder.toString();
+    }
+
+    @Override
+    public AxConcept copyTo(AxConcept target) {
+        final Object copyObject = ((target == null) ? new DummyEntity() : target);
+        if (copyObject instanceof DummyEntity) {
+            final DummyEntity copy = ((DummyEntity) copyObject);
+            if (this.checkSetKey()) {
+                copy.setKey(new AxReferenceKey(key));
+            } else {
+                copy.key = null;
+            }
+            copy.doubleValue = doubleValue;
+            return copy;
+        } else {
+            return null;
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((key == null) ? 0 : key.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (this == obj) {
+            return true;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        DummyEntity other = (DummyEntity) obj;
+        if (key == null) {
+            if (other.key != null) {
+                return false;
+            }
+        } else if (!key.equals(other.key)) {
+            return false;
+        }
+        if (doubleValue != other.doubleValue) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public int compareTo(AxConcept otherObj) {
+        if (otherObj == null) {
+            return -1;
+        }
+        if (this == otherObj) {
+            return 0;
+        }
+        DummyEntity other = (DummyEntity) otherObj;
+        if (key == null) {
+            if (other.key != null) {
+                return 1;
+            }
+        } else if (!key.equals(other.key)) {
+            return key.compareTo(other.key);
+        }
+        if (doubleValue != other.doubleValue) {
+            return Double.valueOf(doubleValue).compareTo(other.doubleValue);
+        }
+
+        return 0;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/ExceptionsTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/ExceptionsTest.java
new file mode 100644
index 000000000..ff87bc2d0
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/ExceptionsTest.java
@@ -0,0 +1,66 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.IOException;
+import org.junit.Test;
+
+
+public class ExceptionsTest {
+
+    @Test
+    public void test() {
+        assertNotNull(new ApexException("Message"));
+        assertNotNull(new ApexException("Message", new AxArtifactKey()));
+        assertNotNull(new ApexException("Message", new IOException()));
+        assertNotNull(new ApexException("Message", new IOException(), new AxArtifactKey()));
+
+        AxArtifactKey key = new AxArtifactKey();
+        ApexException ae = new ApexException("Message", new IOException("IO exception message"), key);
+        assertEquals("Message\ncaused by: Message\ncaused by: IO exception message", ae.getCascadedMessage());
+        assertEquals(key, ae.getObject());
+
+        assertNotNull(new ApexRuntimeException("Message"));
+        assertNotNull(new ApexRuntimeException("Message", new AxArtifactKey()));
+        assertNotNull(new ApexRuntimeException("Message", new IOException()));
+        assertNotNull(new ApexRuntimeException("Message", new IOException(), new AxArtifactKey()));
+
+        AxArtifactKey rkey = new AxArtifactKey();
+        ApexRuntimeException re = new ApexRuntimeException("Runtime Message",
+                        new IOException("IO runtime exception message"), rkey);
+        assertEquals("Runtime Message\ncaused by: Runtime Message\ncaused by: IO runtime exception message",
+                        re.getCascadedMessage());
+        assertEquals(key, re.getObject());
+
+        assertNotNull(new ApexConceptException("Message"));
+        assertNotNull(new ApexConceptException("Message", new IOException()));
+
+        AxArtifactKey ckey = new AxArtifactKey();
+        ApexException ace = new ApexException("Concept Message", new IOException("IO concept exception message"), ckey);
+        assertEquals("Concept Message\ncaused by: Concept Message\ncaused by: IO concept exception message",
+                        ace.getCascadedMessage());
+        assertEquals(ckey, ace.getObject());
+    }
+
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/ValidationTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/ValidationTest.java
new file mode 100644
index 000000000..21ae9b65c
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/concepts/ValidationTest.java
@@ -0,0 +1,90 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+public class ValidationTest {
+
+    @Test
+    public void test() {
+        AxValidationResult result = new AxValidationResult();
+        AxReferenceKey refKey = new AxReferenceKey("PK", "0.0.1", "PLN", "LN");
+        result = refKey.validate(result);
+
+        assertNotNull(result);
+        assertTrue(result.isOk());
+        assertTrue(result.isValid());
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+        assertNotNull(result.getMessageList());
+
+        AxValidationMessage vmess0 = new AxValidationMessage(AxArtifactKey.getNullKey(), AxArtifactKey.class,
+                        ValidationResult.VALID, "Some message");
+        result.addValidationMessage(vmess0);
+
+        assertTrue(result.isOk());
+        assertTrue(result.isValid());
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+        assertNotNull(result.getMessageList());
+        assertNotNull("hello", result.toString());
+
+        AxValidationMessage vmess1 = new AxValidationMessage(AxArtifactKey.getNullKey(), AxArtifactKey.class,
+                        ValidationResult.OBSERVATION, "Some message");
+        result.addValidationMessage(vmess1);
+
+        assertTrue(result.isOk());
+        assertTrue(result.isValid());
+        assertEquals(AxValidationResult.ValidationResult.OBSERVATION, result.getValidationResult());
+        assertNotNull(result.getMessageList());
+        assertNotNull("hello", result.toString());
+
+        AxValidationMessage vmess2 = new AxValidationMessage(AxArtifactKey.getNullKey(), AxArtifactKey.class,
+                        ValidationResult.WARNING, "Some message");
+        result.addValidationMessage(vmess2);
+
+        assertFalse(result.isOk());
+        assertTrue(result.isValid());
+        assertEquals(AxValidationResult.ValidationResult.WARNING, result.getValidationResult());
+        assertNotNull(result.getMessageList());
+        assertNotNull("hello", result.toString());
+
+        AxValidationMessage vmess3 = new AxValidationMessage(AxArtifactKey.getNullKey(), AxArtifactKey.class,
+                        ValidationResult.INVALID, "Some message");
+        result.addValidationMessage(vmess3);
+
+        assertFalse(result.isOk());
+        assertFalse(result.isValid());
+        assertEquals(AxValidationResult.ValidationResult.INVALID, result.getValidationResult());
+        assertNotNull(result.getMessageList());
+        assertNotNull("hello", result.toString());
+
+        assertEquals(AxValidationResult.ValidationResult.INVALID, result.getMessageList().get(3).getValidationResult());
+        assertEquals("Some message", result.getMessageList().get(3).getMessage());
+        assertEquals(AxArtifactKey.class.getName(), result.getMessageList().get(3).getObservedClass());
+        assertEquals(AxArtifactKey.getNullKey(), result.getMessageList().get(3).getObservedKey());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelExceptionTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelExceptionTest.java
new file mode 100644
index 000000000..2571ea65b
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelExceptionTest.java
@@ -0,0 +1,39 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.IOException;
+import org.junit.Test;
+
+public class ApexModelExceptionTest {
+
+    @Test
+    public void test() {
+        assertNotNull(new ApexModelException("Message"));
+        assertNotNull(new ApexModelException("Message", new IOException()));
+
+        ApexModelException ame = new ApexModelException("Message", new IOException("IO exception message"));
+        assertEquals("Message\ncaused by: Message\ncaused by: IO exception message", ame.getCascadedMessage());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelFileWriterTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelFileWriterTest.java
new file mode 100644
index 000000000..0f8f956ab
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelFileWriterTest.java
@@ -0,0 +1,94 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+
+public class ApexModelFileWriterTest {
+
+    @Test
+    public void testModelFileWriter() throws IOException, ApexException {
+        ApexModelFileWriter<AxModel> modelFileWriter = new ApexModelFileWriter<>(true);
+
+        modelFileWriter.setValidate(true);
+        assertTrue(modelFileWriter.isValidate());
+
+        File tempFile = File.createTempFile("ApexFileWriterTest", "test");
+        File tempDir = tempFile.getParentFile();
+
+        File jsonTempFile = new File(tempDir.getAbsolutePath() + "/aaa/ApexFileWriterTest.json");
+
+        AxModel model = new DummyApexBasicModelCreator().getModel();
+
+        modelFileWriter.apexModelWriteJsonFile(model, AxModel.class, jsonTempFile.getAbsolutePath());
+
+        jsonTempFile.delete();
+        new File(tempDir.getAbsolutePath() + "/aaa").delete();
+        new File(tempDir.getAbsolutePath() + "/ccc").delete();
+
+        jsonTempFile = new File(tempDir.getAbsolutePath() + "/aaa/bbb/ApexFileWriterTest.json");
+
+        modelFileWriter.apexModelWriteJsonFile(model, AxModel.class, jsonTempFile.getAbsolutePath());
+
+        jsonTempFile.delete();
+
+        new File(tempDir.getAbsolutePath() + "/aaa/bbb").delete();
+        new File(tempDir.getAbsolutePath() + "/aaa").delete();
+        new File(tempDir.getAbsolutePath() + "/ccc/ddd").delete();
+        new File(tempDir.getAbsolutePath() + "/ccc").delete();
+
+        File dirA = new File(tempDir.getAbsolutePath() + "/aaa");
+        // File dirB = new File(tempDir.getAbsolutePath() + "/aaa/bbb");
+        dirA.createNewFile();
+        // dirB.createNewFile();
+
+        jsonTempFile = new File(tempDir.getAbsolutePath() + "/aaa/bbb/ApexFileWriterTest.json");
+        final File jsonTempFile01 = jsonTempFile;
+        assertThatThrownBy(
+            () -> modelFileWriter.apexModelWriteJsonFile(model, AxModel.class, jsonTempFile01.getAbsolutePath()))
+                .hasMessageContaining("could not create directory");
+
+        dirA.delete();
+
+        dirA = new File(tempDir.getAbsolutePath() + "/aaa");
+        File fileB = new File(tempDir.getAbsolutePath() + "/aaa/bbb");
+        dirA.mkdir();
+        fileB.createNewFile();
+
+        jsonTempFile = new File(tempDir.getAbsolutePath() + "/aaa/bbb/ApexFileWriterTest.json");
+
+        File jsonTempFile02 = jsonTempFile;
+        assertThatThrownBy(
+            () -> modelFileWriter.apexModelWriteJsonFile(model, AxModel.class, jsonTempFile02.getAbsolutePath()))
+                .hasMessageContaining("error processing file");
+
+        fileB.delete();
+        dirA.delete();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelReaderTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelReaderTest.java
new file mode 100644
index 000000000..1152771ea
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelReaderTest.java
@@ -0,0 +1,105 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileReader;
+import java.io.IOException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ApexModelReaderTest {
+    @Test
+    public void testModelReader() throws IOException, ApexException {
+        AxModel model = new DummyApexBasicModelCreator().getModel();
+        AxModel invalidModel = new DummyApexBasicModelCreator().getInvalidModel();
+
+        ApexModelWriter<AxModel> modelWriter = new ApexModelWriter<AxModel>(AxModel.class);
+        modelWriter.setValidate(true);
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        modelWriter.write(model, baos);
+
+        ByteArrayOutputStream baosInvalid = new ByteArrayOutputStream();
+        modelWriter.setValidate(false);
+        modelWriter.write(invalidModel, baosInvalid);
+
+        ApexModelReader<AxModel> modelReader = new ApexModelReader<AxModel>(AxModel.class, true);
+
+        modelReader.setValidate(true);
+        assertTrue(modelReader.isValidate());
+
+        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+        AxModel readModel = modelReader.read(bais);
+        assertEquals(model, readModel);
+
+        ByteArrayInputStream baisInvalid = new ByteArrayInputStream(baosInvalid.toByteArray());
+        assertThatThrownBy(() -> modelReader.read(baisInvalid))
+            .hasMessageStartingWith("Apex concept validation failed");
+        modelReader.setValidate(false);
+        assertFalse(modelReader.isValidate());
+
+        ByteArrayInputStream bais2 = new ByteArrayInputStream(baos.toByteArray());
+        AxModel readModel2 = modelReader.read(bais2);
+        assertEquals(model, readModel2);
+
+        ByteArrayOutputStream baosJson = new ByteArrayOutputStream();
+        modelWriter.write(model, baosJson);
+
+        ByteArrayInputStream baisJson = new ByteArrayInputStream(baosJson.toByteArray());
+        AxModel readModelJson = modelReader.read(baisJson);
+        assertEquals(model, readModelJson);
+
+        String dummyString = "SomeDummyText";
+        ByteArrayInputStream baisDummy = new ByteArrayInputStream(dummyString.getBytes());
+        assertThatThrownBy(() -> modelReader.read(baisDummy))
+            .hasMessageContaining("Unable to unmarshal Apex concept");
+        ByteArrayInputStream nullBais = null;
+        assertThatThrownBy(() -> modelReader.read(nullBais))
+            .hasMessage("concept stream may not be null");
+
+        assertThatThrownBy(() -> {
+            FileInputStream fis = new FileInputStream(new File("somewhere/over/the/rainbow"));
+            modelReader.read(fis);
+        }).hasMessageContaining("rainbow");
+        final File tempFile = File.createTempFile("Apex", "Dummy");
+        BufferedReader br = new BufferedReader(new FileReader(tempFile));
+        br.close();
+        assertThatThrownBy(() -> modelReader.read(br))
+             .hasMessage("Unable to read Apex concept ");
+        tempFile.delete();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelSaverTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelSaverTest.java
new file mode 100644
index 000000000..c95106aa8
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelSaverTest.java
@@ -0,0 +1,52 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.junit.Assert.assertNotNull;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+
+public class ApexModelSaverTest {
+
+    @Test
+    public void testModelSaver() throws IOException, ApexException {
+        AxModel model = new DummyApexBasicModelCreator().getModel();
+        assertNotNull(model);
+
+        Path tempPath = Files.createTempDirectory("ApexTest");
+        assertNotNull(tempPath);
+
+        ApexModelSaver<AxModel> modelSaver =
+            new ApexModelSaver<AxModel>(AxModel.class, model, tempPath.toAbsolutePath().toString());
+        assertNotNull(modelSaver);
+        modelSaver.apexModelWriteJson();
+
+        Files.deleteIfExists(new File(tempPath.toAbsolutePath() + "/BasicModel.json").toPath());
+        Files.deleteIfExists(tempPath);
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelStringWriterTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelStringWriterTest.java
new file mode 100644
index 000000000..13e72d3e2
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelStringWriterTest.java
@@ -0,0 +1,63 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+
+public class ApexModelStringWriterTest {
+
+    @Test
+    public void testModelStringWriter() throws IOException, ApexException {
+        AxModel basicModel = new DummyApexBasicModelCreator().getModel();
+        assertNotNull(basicModel);
+
+        AxKeyInfo intKeyInfo = basicModel.getKeyInformation().get("IntegerKIKey");
+        AxKeyInfo floatKeyInfo = basicModel.getKeyInformation().get("FloatKIKey");
+
+        // Ensure marshalling is OK
+        ApexModelStringWriter<AxKeyInfo> stringWriter = new ApexModelStringWriter<AxKeyInfo>(true);
+
+        assertNotNull(stringWriter.writeJsonString(intKeyInfo, AxKeyInfo.class));
+        assertNotNull(stringWriter.writeJsonString(floatKeyInfo, AxKeyInfo.class));
+
+        assertNotNull(stringWriter.writeString(intKeyInfo, AxKeyInfo.class));
+        assertNotNull(stringWriter.writeString(floatKeyInfo, AxKeyInfo.class));
+
+        assertNotNull(stringWriter.writeString(intKeyInfo, AxKeyInfo.class));
+        assertNotNull(stringWriter.writeString(floatKeyInfo, AxKeyInfo.class));
+
+        assertThatThrownBy(() -> stringWriter.writeString(null, AxKeyInfo.class)).hasMessage("concept may not be null");
+        assertThatThrownBy(() -> stringWriter.writeString(null, AxKeyInfo.class)).hasMessage("concept may not be null");
+        assertThatThrownBy(() -> stringWriter.writeJsonString(null, AxKeyInfo.class))
+            .hasMessage("error writing JSON string");
+        stringWriter.setValidate(true);
+        assertTrue(stringWriter.isValidate());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelWriterTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelWriterTest.java
new file mode 100644
index 000000000..063855976
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/ApexModelWriterTest.java
@@ -0,0 +1,67 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertTrue;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ApexModelWriterTest {
+    @Test
+    public void testModelWriter() throws IOException, ApexException {
+        ApexModelWriter<AxModel> modelWriter = new ApexModelWriter<AxModel>(AxModel.class);
+
+        modelWriter.setValidate(true);
+        assertTrue(modelWriter.isValidate());
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+        AxModel model = new DummyApexBasicModelCreator().getModel();
+
+        modelWriter.write(model, baos);
+
+        modelWriter.setValidate(false);
+        modelWriter.write(model, baos);
+
+        modelWriter.setValidate(true);
+        model.getKeyInformation().getKeyInfoMap().clear();
+        assertThatThrownBy(() -> modelWriter.write(model, baos))
+            .hasMessageContaining("Apex concept (BasicModel:0.0.1) validation failed");
+        model.getKeyInformation().generateKeyInfo(model);
+
+        assertThatThrownBy(() -> modelWriter.write(null, baos))
+            .hasMessage("concept may not be null");
+
+        ByteArrayOutputStream nullBaos = null;
+        assertThatThrownBy(() -> modelWriter.write(model, nullBaos))
+            .hasMessage("concept stream may not be null");
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/DummyApexBasicModelCreator.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/DummyApexBasicModelCreator.java
new file mode 100644
index 000000000..353722b2d
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/DummyApexBasicModelCreator.java
@@ -0,0 +1,123 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import java.util.UUID;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+
+public class DummyApexBasicModelCreator implements TestApexModelCreator<AxModel> {
+
+    @Override
+    public AxModel getModel() {
+        AxModel basicModel = new AxModel();
+
+        basicModel.setKey(new AxArtifactKey("BasicModel", "0.0.1"));
+        basicModel.setKeyInformation(new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1")));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKey(), new AxKeyInfo(basicModel.getKey()));
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKeyInformation().getKey(),
+                        new AxKeyInfo(basicModel.getKeyInformation().getKey()));
+
+        AxKeyInfo intKeyInfo = new AxKeyInfo(new AxArtifactKey("IntegerKIKey", "0.0.1"), UUID.randomUUID(),
+                        "IntegerKIKey description");
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKeyInfo.getKey(), new AxKeyInfo(intKeyInfo.getKey()));
+
+        AxKeyInfo floatKeyInfo = new AxKeyInfo(new AxArtifactKey("FloatKIKey", "0.0.1"), UUID.randomUUID(),
+                        "FloatKIKey description");
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKeyInfo.getKey(), new AxKeyInfo(floatKeyInfo.getKey()));
+
+        return basicModel;
+    }
+
+    @Override
+    public final AxModel getMalstructuredModel() {
+        AxModel basicModel = new AxModel();
+
+        // Note: No Data types
+        basicModel.setKey(new AxArtifactKey("BasicModelKey", "0.0.1"));
+        basicModel.setKeyInformation(new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1")));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKey(), new AxKeyInfo(basicModel.getKey(),
+                        UUID.fromString("00000000-0000-0000-0000-000000000000"),
+                        "\nbasic model description\nThis is a multi line description\nwith another line of text."));
+
+        return basicModel;
+    }
+
+    @Override
+    public final AxModel getObservationModel() {
+        AxModel basicModel = getModel();
+
+        // Set key information as blank
+        basicModel.getKeyInformation().getKeyInfoMap().get(basicModel.getKey()).setDescription("");
+
+        return basicModel;
+    }
+
+    @Override
+    public final AxModel getWarningModel() {
+        AxModel basicModel = getModel();
+
+        // Add unreferenced key information
+        AxKeyInfo unreferencedKeyInfo0 = new AxKeyInfo(new AxArtifactKey("Unref0", "0.0.1"));
+        AxKeyInfo unreferencedKeyInfo1 = new AxKeyInfo(new AxArtifactKey("Unref1", "0.0.1"));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(unreferencedKeyInfo0.getKey(), unreferencedKeyInfo0);
+        basicModel.getKeyInformation().getKeyInfoMap().put(unreferencedKeyInfo1.getKey(), unreferencedKeyInfo1);
+
+        return basicModel;
+    }
+
+    @Override
+    public final AxModel getInvalidModel() {
+        AxModel basicModel = new AxModel();
+
+        basicModel.setKey(new AxArtifactKey("BasicModelKey", "0.0.1"));
+        basicModel.setKeyInformation(new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1")));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKey(), new AxKeyInfo(basicModel.getKey(),
+                        UUID.fromString("00000000-0000-0000-0000-000000000000"),
+                        "nbasic model description\nThis is a multi line description\nwith another line of text."));
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKeyInformation().getKey(),
+                        new AxKeyInfo(basicModel.getKeyInformation().getKey(),
+                                        UUID.fromString("00000000-0000-0000-0000-000000000000"), ""));
+
+        return basicModel;
+    }
+
+    /**
+     * Get the model with its references.
+     * @return the model with its references
+     */
+    public final DummyAxModelWithReferences getModelWithReferences() {
+        AxModel model = getModel();
+
+        DummyAxModelWithReferences modelWithReferences = new DummyAxModelWithReferences(model.getKey());
+        modelWithReferences.setKeyInformation(model.getKeyInformation());
+        modelWithReferences.setReferenceKeyList();
+
+        return modelWithReferences;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/DummyAxModelWithReferences.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/DummyAxModelWithReferences.java
new file mode 100644
index 000000000..887755d03
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/DummyAxModelWithReferences.java
@@ -0,0 +1,71 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+
+public class DummyAxModelWithReferences extends AxModel {
+    private static final long serialVersionUID = -8194956638511120008L;
+
+    private List<AxKey> extrakeyList = new ArrayList<>();
+    
+    public DummyAxModelWithReferences(final AxArtifactKey key) {
+        super(key);
+    }
+    
+    @Override
+    public List<AxKey> getKeys() {
+        List<AxKey> keys = super.getKeys();
+        keys.addAll(extrakeyList);
+
+        return keys;
+    }
+
+    public List<AxKey> getExtrakeyList() {
+        return extrakeyList;
+    }
+
+    /**
+     * Set the reference key list.
+     */
+    public void setReferenceKeyList() {
+        List<AxKey> keys = super.getKeys();
+        
+        for (AxKey key: keys) {
+            AxArtifactKey akey = (AxArtifactKey) key;
+            AxReferenceKey keyRef = new AxReferenceKey(akey, akey.getName());
+            extrakeyList.add(keyRef);
+        }
+    }
+    
+    public void addKey(final AxKey akey) {
+        extrakeyList.add(akey);
+    }
+    
+    public void removeKey(final AxKey akey) {
+        extrakeyList.remove(akey);
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexBasicModelConceptsTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexBasicModelConceptsTest.java
new file mode 100644
index 000000000..905a27f38
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexBasicModelConceptsTest.java
@@ -0,0 +1,294 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.util.List;
+import java.util.Set;
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyUse;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+import org.onap.policy.apex.model.basicmodel.service.ModelService;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+
+public class SupportApexBasicModelConceptsTest {
+    TestApexModel<AxModel> testApexModel;
+
+    @Before
+    public void setup() throws Exception {
+        testApexModel = new TestApexModel<AxModel>(AxModel.class, new DummyApexBasicModelCreator());
+    }
+
+    @Test
+    public void testModelConcepts() {
+        final AxModel model = testApexModel.getModel();
+        assertNotNull(model);
+        model.clean();
+        assertNotNull(model);
+
+        AxValidationResult result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.WARNING, result.getValidationResult());
+
+        model.register();
+        assertEquals(model.getKeyInformation(), ModelService.getModel(AxKeyInformation.class));
+
+        final AxModel clonedModel = new AxModel(model);
+        assertTrue(clonedModel.toString().startsWith("AxModel:(key=AxArtifactKey:(name=BasicModel"));
+
+        assertNotEquals(0, model.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(model, model); // NOSONAR
+        assertEquals(model, clonedModel);
+        assertNotNull(model);
+        assertNotEquals(model, (Object) "Hello");
+        clonedModel.getKey().setVersion("0.0.2");
+        assertNotEquals(model, clonedModel);
+        clonedModel.getKey().setVersion("0.0.1");
+
+        assertEquals(0, model.compareTo(model));
+        assertNotEquals(0, model.compareTo(null));
+        assertNotEquals(0, model.compareTo(new AxReferenceKey()));
+        assertEquals(0, model.compareTo(clonedModel));
+        clonedModel.getKey().setVersion("0.0.2");
+        assertNotEquals(0, model.compareTo(clonedModel));
+        clonedModel.getKey().setVersion("0.0.1");
+
+        assertNotNull(model.getKeys());
+
+        model.getKeyInformation().generateKeyInfo(model);
+        assertNotNull(model.getKeyInformation());
+
+    }
+
+    @Test
+    public void testKeyInformation() {
+
+        final AxModel model = testApexModel.getModel();
+        final AxKeyInformation keyI = model.getKeyInformation();
+        final AxKeyInformation clonedKeyI = new AxKeyInformation(keyI);
+
+        assertNotNull(keyI);
+        assertNotEquals(keyI, (Object) new AxArtifactKey());
+        assertEquals(keyI, clonedKeyI);
+
+        clonedKeyI.setKey(new AxArtifactKey());
+        assertNotEquals(keyI, clonedKeyI);
+        clonedKeyI.setKey(keyI.getKey());
+
+        assertEquals(0, keyI.compareTo(keyI));
+        assertEquals(0, keyI.compareTo(clonedKeyI));
+        assertNotEquals(0, keyI.compareTo(null));
+        assertNotEquals(0, keyI.compareTo(new AxArtifactKey()));
+
+        clonedKeyI.setKey(new AxArtifactKey());
+        assertNotEquals(0, keyI.compareTo(clonedKeyI));
+        clonedKeyI.setKey(keyI.getKey());
+        assertEquals(0, keyI.compareTo(clonedKeyI));
+
+        clonedKeyI.getKeyInfoMap().clear();
+        assertNotEquals(0, keyI.compareTo(clonedKeyI));
+
+        AxKeyInfo keyInfo = keyI.get("BasicModel");
+        assertNotNull(keyInfo);
+
+        keyInfo = keyI.get(new AxArtifactKey("BasicModel", "0.0.1"));
+        assertNotNull(keyInfo);
+
+        Set<AxKeyInfo> keyInfoSet = keyI.getAll("BasicModel");
+        assertNotNull(keyInfoSet);
+
+        keyInfoSet = keyI.getAll("BasicModel", "0..0.1");
+        assertNotNull(keyInfoSet);
+
+        List<AxKey> keys = model.getKeys();
+        assertNotEquals(0, keys.size());
+
+        keys = keyI.getKeys();
+        assertNotEquals(0, keys.size());
+
+        model.getKeyInformation().generateKeyInfo(model);
+        assertNotNull(model.getKeyInformation());
+        model.getKeyInformation().getKeyInfoMap().clear();
+        model.getKeyInformation().generateKeyInfo(model);
+        assertNotNull(model.getKeyInformation());
+    }
+
+    @Test
+    public void testClonedKey() {
+        final AxModel model = testApexModel.getModel();
+        final AxKeyInformation keyI = model.getKeyInformation();
+        final AxKeyInformation clonedKeyI = new AxKeyInformation(keyI);
+        AxValidationResult result = new AxValidationResult();
+
+        clonedKeyI.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        clonedKeyI.setKey(keyI.getKey());
+
+        clonedKeyI.getKeyInfoMap().clear();
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        clonedKeyI.generateKeyInfo(model);
+
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        clonedKeyI.getKeyInfoMap().put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        clonedKeyI.getKeyInfoMap().clear();
+        clonedKeyI.generateKeyInfo(model);
+
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        clonedKeyI.getKeyInfoMap().put(new AxArtifactKey("SomeKey", "0.0.1"), null);
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        clonedKeyI.getKeyInfoMap().clear();
+        clonedKeyI.generateKeyInfo(model);
+
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxKeyInfo mk = clonedKeyI.get(new AxArtifactKey("BasicModel", "0.0.1"));
+        assertNotNull(mk);
+        mk.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        clonedKeyI.getKeyInfoMap().clear();
+        clonedKeyI.generateKeyInfo(model);
+
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxModel clonedModel = new AxModel(model);
+        clonedModel.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = clonedModel.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        clonedModel.setKey(model.getKey());
+        result = new AxValidationResult();
+        result = clonedKeyI.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+    }
+
+    @Test
+    public void testModelConceptsWithReferences() {
+        final DummyAxModelWithReferences mwr = new DummyApexBasicModelCreator().getModelWithReferences();
+        assertNotNull(mwr);
+        mwr.getKeyInformation().getKeyInfoMap().clear();
+        mwr.getKeyInformation().generateKeyInfo(mwr);
+
+        AxValidationResult result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Duplicate key error
+        mwr.addKey(mwr.getKey());
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        mwr.removeKey(mwr.getKey());
+
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Null Reference Key
+        mwr.addKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        mwr.removeKey(AxReferenceKey.getNullKey());
+
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Duplicate Reference Key
+        final AxReferenceKey rKey = new AxReferenceKey(mwr.getKey(), "LocalName");
+        mwr.addKey(rKey);
+        mwr.addKey(rKey);
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        mwr.removeKey(rKey);
+        mwr.removeKey(rKey);
+
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Key Use is legal
+        final AxKeyUse keyU = new AxKeyUse(mwr.getKey());
+        mwr.addKey(keyU);
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+        mwr.removeKey(keyU);
+
+        // Key Use on bad artifact key
+        final AxKeyUse keyBadUsage = new AxKeyUse(new AxArtifactKey("SomeKey", "0.0.1"));
+        mwr.addKey(keyBadUsage);
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        mwr.removeKey(keyBadUsage);
+
+        // Key Use on bad reference key
+        final AxKeyUse keyBadReferenceUsage = new AxKeyUse(new AxReferenceKey("SomeKey", "0.0.1", "Local"));
+        mwr.addKey(keyBadReferenceUsage);
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        mwr.removeKey(keyBadReferenceUsage);
+
+        result = new AxValidationResult();
+        result = mwr.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexBasicModelTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexBasicModelTest.java
new file mode 100644
index 000000000..68f755886
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexBasicModelTest.java
@@ -0,0 +1,116 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020-2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+
+public class SupportApexBasicModelTest {
+    // As there are no real concepts in a basic model, this is as near to a valid model as we can get
+    private static final String VALID_MODEL_STRING = "\n" + "***warnings issued during validation of model***\n"
+                    + "AxArtifactKey:(name=FloatKIKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts"
+                    + ".AxModel:WARNING:key not found for key information entry\n"
+                    + "AxArtifactKey:(name=IntegerKIKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts"
+                    + ".AxModel:WARNING:key not found for key information entry\n" + "********************************";
+
+    private static final String WARNING_MODEL_STRING = "\n" + "***warnings issued during validation of model***\n"
+                    + "AxArtifactKey:(name=FloatKIKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts"
+                    + ".AxModel:WARNING:key not found for key information entry\n"
+                    + "AxArtifactKey:(name=IntegerKIKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts"
+                    + ".AxModel:WARNING:key not found for key information entry\n"
+                    + "AxArtifactKey:(name=Unref0,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts"
+                    + ".AxModel:WARNING:key not found for key information entry\n"
+                    + "AxArtifactKey:(name=Unref1,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts"
+                    + ".AxModel:WARNING:key not found for key information entry\n" + "********************************";
+
+    private static final String INVALID_MODEL_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=BasicModelKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts."
+                    + "AxKeyInfo:WARNING:UUID is a zero UUID: 00000000-0000-0000-0000-000000000000\n"
+                    + "AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts."
+                    + "AxKeyInfo:OBSERVATION:description is blank\n"
+                    + "AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts."
+                    + "AxKeyInfo:WARNING:UUID is a zero UUID: 00000000-0000-0000-0000-000000000000\n"
+                    + "AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts."
+                    + "AxKeyInformation:INVALID:duplicate UUID found on keyInfoMap entry AxArtifactKey:"
+                    + "(name=KeyInfoMapKey,version=0.0.1):00000000-0000-0000-0000-000000000000\n"
+                    + "********************************";
+
+    private static final String INVALID_MODEL_MALSTRUCTURED_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=BasicModelKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts."
+                    + "AxKeyInfo:WARNING:UUID is a zero UUID: 00000000-0000-0000-0000-000000000000\n"
+                    + "AxArtifactKey:(name=BasicModelKey,version=0.0.1):org.onap.policy.apex.model.basicmodel.concepts."
+                    + "AxModel:INVALID:key information not found for key "
+                    + "AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1)\n" + "********************************";
+
+    TestApexModel<AxModel> testApexModel;
+
+    /**
+     * Set up the test.
+     *
+     * @throws Exception any exception thrown by the test
+     */
+    @Before
+    public void setup() throws Exception {
+        testApexModel = new TestApexModel<AxModel>(AxModel.class, new DummyApexBasicModelCreator());
+    }
+
+    @Test
+    public void testModelValid() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelValid();
+        assertEquals(VALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateObservation() throws Exception {
+        assertThatThrownBy(testApexModel::testApexModelVaidateObservation)
+            .hasMessage("model should have observations");
+    }
+
+    @Test
+    public void testApexModelVaidateWarning() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateWarning();
+        assertEquals(WARNING_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateInvalidModel() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateInvalidModel();
+        assertEquals(INVALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateMalstructured() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateMalstructured();
+        assertEquals(INVALID_MODEL_MALSTRUCTURED_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelWriteReadJson() throws Exception {
+        testApexModel.testApexModelWriteReadJson();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator0.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator0.java
new file mode 100644
index 000000000..e835bc0fc
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator0.java
@@ -0,0 +1,64 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+
+public class SupportApexModelCreator0 implements TestApexModelCreator<AxModel> {
+
+    @Override
+    public AxModel getModel() {
+        AxModel basicModel = new AxModel();
+
+        basicModel.setKey(new AxArtifactKey("BasicModel", "0.0.1"));
+        basicModel.setKeyInformation(new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1")));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKey(), new AxKeyInfo(basicModel.getKey()));
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKeyInformation().getKey(),
+                        new AxKeyInfo(basicModel.getKeyInformation().getKey()));
+
+        return basicModel;
+    }
+
+    @Override
+    public final AxModel getMalstructuredModel() {
+        return getModel();
+    }
+
+    @Override
+    public final AxModel getObservationModel() {
+        return getModel();
+    }
+
+    @Override
+    public final AxModel getWarningModel() {
+        return getModel();
+    }
+
+    @Override
+    public final AxModel getInvalidModel() {
+        return getModel();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator1.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator1.java
new file mode 100644
index 000000000..9ad34a38c
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator1.java
@@ -0,0 +1,68 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import java.util.UUID;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+
+public class SupportApexModelCreator1 implements TestApexModelCreator<AxModel> {
+
+    @Override
+    public AxModel getModel() {
+        return getInvalidModel();
+    }
+
+    @Override
+    public final AxModel getMalstructuredModel() {
+        return getInvalidModel();
+    }
+
+    @Override
+    public final AxModel getObservationModel() {
+        return getInvalidModel();
+    }
+
+    @Override
+    public final AxModel getWarningModel() {
+        return getInvalidModel();
+    }
+
+    @Override
+    public final AxModel getInvalidModel() {
+        AxModel basicModel = new AxModel();
+
+        basicModel.setKey(new AxArtifactKey("BasicModelKey", "0.0.1"));
+        basicModel.setKeyInformation(new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1")));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKey(), new AxKeyInfo(basicModel.getKey(),
+                        UUID.fromString("00000000-0000-0000-0000-000000000000"),
+                        "nbasic model description\nThis is a multi line description\nwith another line of text."));
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKeyInformation().getKey(),
+                        new AxKeyInfo(basicModel.getKeyInformation().getKey(),
+                                        UUID.fromString("00000000-0000-0000-0000-000000000000"), ""));
+
+        return basicModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator2.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator2.java
new file mode 100644
index 000000000..0ab7aab7f
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportApexModelCreator2.java
@@ -0,0 +1,64 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+
+public class SupportApexModelCreator2 implements TestApexModelCreator<AxModel> {
+
+    @Override
+    public AxModel getModel() {
+        AxModel basicModel = new AxModel();
+
+        basicModel.setKey(new AxArtifactKey("BasicModel", "0.0.1"));
+        basicModel.setKeyInformation(new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1")));
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKey(), new AxKeyInfo(basicModel.getKey()));
+        basicModel.getKeyInformation().getKeyInfoMap().put(basicModel.getKeyInformation().getKey(),
+                        new AxKeyInfo(basicModel.getKeyInformation().getKey()));
+        basicModel.getKeyInformation().get("BasicModel").setDescription("");
+        return basicModel;
+    }
+
+    @Override
+    public final AxModel getMalstructuredModel() {
+        return getModel();
+    }
+
+    @Override
+    public final AxModel getObservationModel() {
+        return getModel();
+    }
+
+    @Override
+    public final AxModel getWarningModel() {
+        return getModel();
+    }
+
+    @Override
+    public final AxModel getInvalidModel() {
+        return getModel();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportBasicModelTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportBasicModelTest.java
new file mode 100644
index 000000000..d55a9da29
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportBasicModelTest.java
@@ -0,0 +1,111 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020-2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+
+public class SupportBasicModelTest {
+
+    @Test
+    public void testNormalModelCreator() throws ApexException {
+        final TestApexModel<AxModel> testApexModel = new TestApexModel<AxModel>(AxModel.class,
+            new DummyApexBasicModelCreator());
+
+        testApexModel.testApexModelValid();
+        assertThatThrownBy(testApexModel::testApexModelVaidateObservation)
+            .hasMessage("model should have observations");
+        testApexModel.testApexModelVaidateWarning();
+        testApexModel.testApexModelVaidateInvalidModel();
+        testApexModel.testApexModelVaidateMalstructured();
+
+        testApexModel.testApexModelWriteReadJson();
+    }
+
+    @Test
+    public void testModelsUnequal() throws ApexException {
+        final TestApexModel<AxModel> testApexModel0 = new TestApexModel<AxModel>(AxModel.class,
+            new DummyApexBasicModelCreator());
+        final TestApexModel<AxModel> testApexModel1 = new TestApexModel<AxModel>(AxModel.class,
+            new DummyApexBasicModelCreator());
+
+        testApexModel1.getModel().getKey().setVersion("0.0.2");
+
+        assertThatThrownBy(() -> testApexModel0.checkModelEquality(testApexModel0.getModel(), testApexModel1.getModel(),
+                "Models are not equal")).hasMessage("Models are not equal");
+    }
+
+    @Test
+    public void testModelCreator0() throws ApexException {
+        final TestApexModel<AxModel> testApexModel = new TestApexModel<AxModel>(AxModel.class,
+            new SupportApexModelCreator0());
+
+        testApexModel.testApexModelValid();
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateObservation())
+            .hasMessage("model should have observations");
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateWarning())
+            .hasMessage("model should have warnings");
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateInvalidModel())
+            .hasMessage("model should not be valid ***validation of model successful***");
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateMalstructured())
+            .hasMessage("model should not be valid ***validation of model successful***");
+    }
+
+    @Test
+    public void testModelCreator1() throws ApexException {
+        final TestApexModel<AxModel> testApexModel = new TestApexModel<AxModel>(AxModel.class,
+            new SupportApexModelCreator1());
+
+        assertThatThrownBy(() -> testApexModel.testApexModelValid())
+            .hasMessageStartingWith("model is invalid");
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateObservation())
+            .hasMessageStartingWith("model is invalid");
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateWarning())
+            .hasMessageStartingWith("model is invalid");
+        testApexModel.testApexModelVaidateInvalidModel();
+        testApexModel.testApexModelVaidateMalstructured();
+    }
+
+    @Test
+    public void testModelCreator2() throws ApexException {
+        final TestApexModel<AxModel> testApexModel = new TestApexModel<AxModel>(AxModel.class,
+            new SupportApexModelCreator2());
+
+        testApexModel.testApexModelValid();
+        testApexModel.testApexModelVaidateObservation();
+        assertThatThrownBy(() -> testApexModel.testApexModelVaidateWarning())
+            .hasMessage("model should have warnings");
+    }
+
+    @Test
+    public void testModelCreator1Json() throws ApexException {
+        final TestApexModel<AxModel> testApexModel = new TestApexModel<AxModel>(AxModel.class,
+            new SupportApexModelCreator1());
+
+        assertThatThrownBy(() -> testApexModel.testApexModelWriteReadJson())
+            .hasMessageStartingWith("error processing file");
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportConceptGetterTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportConceptGetterTest.java
new file mode 100644
index 000000000..1783fc00f
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/handling/SupportConceptGetterTest.java
@@ -0,0 +1,217 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020-2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.handling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.UUID;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxModel;
+
+public class SupportConceptGetterTest {
+
+    private static final AxKeyInfo intKI01 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey01", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey01 description");
+    private static final AxKeyInfo intKI11 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey11", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey11 description");
+    private static final AxKeyInfo intKI21 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey21", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey21 description");
+    private static final AxKeyInfo intKI22 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey22", "0.0.2"),
+            UUID.randomUUID(), "IntegerKIKey22 description");
+    private static final AxKeyInfo intKI23 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey23", "0.0.3"),
+            UUID.randomUUID(), "IntegerKIKey23 description");
+    private static final AxKeyInfo intKI24 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey24", "0.0.4"),
+            UUID.randomUUID(), "IntegerKIKey24 description");
+    private static final AxKeyInfo intKI25 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey25", "0.0.5"),
+            UUID.randomUUID(), "IntegerKIKey25 description");
+    private static final AxKeyInfo intKI26 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey26", "0.0.6"),
+            UUID.randomUUID(), "IntegerKIKey26 description");
+    private static final AxKeyInfo intKI31 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey31", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey31 description");
+    private static final AxKeyInfo intKI41 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey41", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey41 description");
+    private static final AxKeyInfo intKI51 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey51", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey51 description");
+    private static final AxKeyInfo intKI52 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey52", "0.0.2"),
+            UUID.randomUUID(), "IntegerKIKey52 description");
+    private static final AxKeyInfo intKI53 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey53", "0.0.3"),
+            UUID.randomUUID(), "IntegerKIKey53 description");
+    private static final AxKeyInfo intKI54 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey54", "0.0.4"),
+            UUID.randomUUID(), "IntegerKIKey54 description");
+    private static final AxKeyInfo intKI61 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey61", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey61 description");
+    private static final AxKeyInfo intKI62 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey62", "0.0.2"),
+            UUID.randomUUID(), "IntegerKIKey62 description");
+    private static final AxKeyInfo intKI63 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey63", "0.0.3"),
+            UUID.randomUUID(), "IntegerKIKey63 description");
+    private static final AxKeyInfo intKI64 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey64", "0.0.4"),
+            UUID.randomUUID(), "IntegerKIKey64 description");
+    private static final AxKeyInfo intKI71 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey71", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey71 description");
+    private static final AxKeyInfo intKI81 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey81", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey81 description");
+    private static final AxKeyInfo intKI91 = new AxKeyInfo(new AxArtifactKey("IntegerKIKey91", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey91 description");
+    private static final AxKeyInfo floatKI01 = new AxKeyInfo(new AxArtifactKey("FloatKIKey01", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey01 description");
+    private static final AxKeyInfo floatKI11 = new AxKeyInfo(new AxArtifactKey("FloatKIKey11", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey11 description");
+    private static final AxKeyInfo floatKI21 = new AxKeyInfo(new AxArtifactKey("FloatKIKey21", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey21 description");
+    private static final AxKeyInfo floatKI31 = new AxKeyInfo(new AxArtifactKey("FloatKIKey31", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey31 description");
+    private static final AxKeyInfo floatKI41 = new AxKeyInfo(new AxArtifactKey("FloatKIKey41", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey41 description");
+    private static final AxKeyInfo floatKI51 = new AxKeyInfo(new AxArtifactKey("FloatKIKey51", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey51 description");
+    private static final AxKeyInfo floatKI61 = new AxKeyInfo(new AxArtifactKey("FloatKIKey61", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey61 description");
+    private static final AxKeyInfo floatKI71 = new AxKeyInfo(new AxArtifactKey("FloatKIKey71", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey71 description");
+    private static final AxKeyInfo floatKI81 = new AxKeyInfo(new AxArtifactKey("FloatKIKey81", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey81 description");
+    private static final AxKeyInfo floatKI82 = new AxKeyInfo(new AxArtifactKey("FloatKIKey82", "0.0.2"),
+            UUID.randomUUID(), "IntegerKIKey82 description");
+    private static final AxKeyInfo floatKI83 = new AxKeyInfo(new AxArtifactKey("FloatKIKey83", "0.0.3"),
+            UUID.randomUUID(), "IntegerKIKey83 description");
+    private static final AxKeyInfo floatKI91 = new AxKeyInfo(new AxArtifactKey("FloatKIKey91", "0.0.1"),
+            UUID.randomUUID(), "IntegerKIKey91 description");
+    private static final AxKeyInfo floatKI92 = new AxKeyInfo(new AxArtifactKey("FloatKIKey92", "0.0.2"),
+            UUID.randomUUID(), "IntegerKIKey92 description");
+    private static final AxKeyInfo floatKI93 = new AxKeyInfo(new AxArtifactKey("FloatKIKey93", "0.0.3"),
+            UUID.randomUUID(), "IntegerKIKey93 description");
+
+    @Test
+    public void testConceptGetterInteger() {
+        AxModel basicModel = setTestBasicModel();
+
+        assertNull(basicModel.getKeyInformation().get("NonExistantKey", "0.0.6"));
+        assertEquals(intKI26, basicModel.getKeyInformation().get("IntegerKIKey26", "0.0.6"));
+        assertEquals(intKI62, basicModel.getKeyInformation().get("IntegerKIKey62", "0.0.2"));
+        assertEquals(intKI21, basicModel.getKeyInformation().get("IntegerKIKey21", "0.0.1"));
+        assertEquals(intKI61, basicModel.getKeyInformation().get("IntegerKIKey61", "0.0.1"));
+
+        assertNull(basicModel.getKeyInformation().get("NonExistantKey"));
+
+        assertEquals(intKI01, basicModel.getKeyInformation().get("IntegerKIKey01"));
+        assertEquals(intKI11, basicModel.getKeyInformation().get("IntegerKIKey11"));
+        assertEquals(intKI26, basicModel.getKeyInformation().get("IntegerKIKey26"));
+        assertEquals(intKI31, basicModel.getKeyInformation().get("IntegerKIKey31"));
+        assertEquals(intKI41, basicModel.getKeyInformation().get("IntegerKIKey41"));
+        assertEquals(intKI54, basicModel.getKeyInformation().get("IntegerKIKey54"));
+        assertEquals(intKI64, basicModel.getKeyInformation().get("IntegerKIKey64"));
+        assertEquals(intKI71, basicModel.getKeyInformation().get("IntegerKIKey71"));
+        assertEquals(intKI81, basicModel.getKeyInformation().get("IntegerKIKey81"));
+        assertEquals(intKI91, basicModel.getKeyInformation().get("IntegerKIKey91"));
+    }
+
+    @Test
+    public void testConceptGetterFloat() {
+        AxModel basicModel = setTestBasicModel();
+
+        assertEquals(floatKI01, basicModel.getKeyInformation().get("FloatKIKey01"));
+        assertEquals(floatKI11, basicModel.getKeyInformation().get("FloatKIKey11"));
+        assertEquals(floatKI21, basicModel.getKeyInformation().get("FloatKIKey21"));
+        assertEquals(floatKI31, basicModel.getKeyInformation().get("FloatKIKey31"));
+        assertEquals(floatKI41, basicModel.getKeyInformation().get("FloatKIKey41"));
+        assertEquals(floatKI51, basicModel.getKeyInformation().get("FloatKIKey51"));
+        assertEquals(floatKI61, basicModel.getKeyInformation().get("FloatKIKey61"));
+        assertEquals(floatKI71, basicModel.getKeyInformation().get("FloatKIKey71"));
+        assertEquals(floatKI83, basicModel.getKeyInformation().get("FloatKIKey83"));
+        assertEquals(floatKI93, basicModel.getKeyInformation().get("FloatKIKey93"));
+    }
+
+    @Test
+    public void testMarshalling() throws IOException, ApexException {
+        AxModel basicModel = setTestBasicModel();
+
+        // Ensure marshalling and unmarshalling is OK
+        ApexModelReader<AxModel> modelReader = new ApexModelReader<AxModel>(AxModel.class);
+        ApexModelFileWriter<AxModel> modelWriter = new ApexModelFileWriter<AxModel>(true);
+
+        modelReader.setValidate(false);
+        modelWriter.setValidate(false);
+
+        File tempJsonFile = File.createTempFile("ApexModel", "json");
+        modelWriter.apexModelWriteJsonFile(basicModel, AxModel.class, tempJsonFile.getCanonicalPath());
+
+        FileInputStream jsonFileInputStream = new FileInputStream(tempJsonFile);
+        AxModel readJsonModel = modelReader.read(jsonFileInputStream);
+        jsonFileInputStream.close();
+        assertEquals(basicModel, readJsonModel);
+        assertEquals(intKI91, readJsonModel.getKeyInformation().get("IntegerKIKey91"));
+        assertNotNull(readJsonModel.getKeyInformation().get("FloatKIKey"));
+        tempJsonFile.delete();
+    }
+
+    private AxModel setTestBasicModel() {
+        AxModel basicModel = new DummyApexBasicModelCreator().getModel();
+        assertNotNull(basicModel);
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI31.getKey(), intKI31);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI24.getKey(), intKI24);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI11.getKey(), intKI11);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI64.getKey(), intKI64);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI41.getKey(), intKI41);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI51.getKey(), intKI51);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI23.getKey(), intKI23);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI81.getKey(), intKI81);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI71.getKey(), intKI71);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI01.getKey(), intKI01);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI91.getKey(), intKI91);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI52.getKey(), intKI52);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI53.getKey(), intKI53);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI62.getKey(), intKI62);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI54.getKey(), intKI54);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI26.getKey(), intKI26);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI22.getKey(), intKI22);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI25.getKey(), intKI25);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI21.getKey(), intKI21);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI61.getKey(), intKI61);
+        basicModel.getKeyInformation().getKeyInfoMap().put(intKI63.getKey(), intKI63);
+
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI11.getKey(), floatKI11);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI83.getKey(), floatKI83);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI51.getKey(), floatKI51);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI71.getKey(), floatKI71);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI21.getKey(), floatKI21);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI81.getKey(), floatKI81);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI92.getKey(), floatKI92);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI91.getKey(), floatKI91);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI01.getKey(), floatKI01);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI82.getKey(), floatKI82);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI61.getKey(), floatKI61);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI41.getKey(), floatKI41);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI31.getKey(), floatKI31);
+        basicModel.getKeyInformation().getKeyInfoMap().put(floatKI93.getKey(), floatKI93);
+
+        return basicModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/basicmodel/service/ModelServiceTest.java b/model/src/test/java/org/onap/policy/apex/model/basicmodel/service/ModelServiceTest.java
new file mode 100644
index 000000000..746e10607
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/basicmodel/service/ModelServiceTest.java
@@ -0,0 +1,65 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.basicmodel.service;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.handling.DummyApexBasicModelCreator;
+
+public class ModelServiceTest {
+
+    @Test
+    public void testModelService() {
+        ModelService.clear();
+
+        assertFalse(ModelService.existsModel(AxKeyInformation.class));
+        assertThatThrownBy(() -> ModelService.getModel(AxKeyInformation.class))
+            .hasMessage("Model for org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation "
+                            + "not found in model service");
+        ModelService.registerModel(AxKeyInformation.class,
+                        new DummyApexBasicModelCreator().getModel().getKeyInformation());
+        assertTrue(ModelService.existsModel(AxKeyInformation.class));
+        assertNotNull(ModelService.getModel(AxKeyInformation.class));
+
+        ModelService.deregisterModel(AxKeyInformation.class);
+
+        assertFalse(ModelService.existsModel(AxKeyInformation.class));
+        assertThatThrownBy(() -> ModelService.getModel(AxKeyInformation.class))
+            .hasMessage("Model for org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation "
+                            + "not found in model service");
+        ModelService.registerModel(AxKeyInformation.class,
+                        new DummyApexBasicModelCreator().getModel().getKeyInformation());
+        assertTrue(ModelService.existsModel(AxKeyInformation.class));
+        assertNotNull(ModelService.getModel(AxKeyInformation.class));
+
+        ModelService.clear();
+        assertFalse(ModelService.existsModel(AxKeyInformation.class));
+        assertThatThrownBy(() -> ModelService.getModel(AxKeyInformation.class))
+            .hasMessage("Model for org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation "
+                            + "not found in model service");
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextAlbumsTest.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextAlbumsTest.java
new file mode 100644
index 000000000..44161b329
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextAlbumsTest.java
@@ -0,0 +1,248 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2021 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Context album tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ContextAlbumsTest {
+
+    @Test
+    public void testNewAxContectAlbum() {
+        assertNotNull(new AxContextAlbum());
+        assertNotNull(new AxContextAlbum(new AxArtifactKey()));
+        assertNotNull(new AxContextAlbum(new AxArtifactKey(), "AlbumScope", false, new AxArtifactKey()));
+    }
+
+    @Test
+    public void testContextAlbums() {
+        final AxArtifactKey albumKey = new AxArtifactKey("AlbumName", "0.0.1");
+        final AxArtifactKey albumSchemaKey = new AxArtifactKey("AlbumSchemaName", "0.0.1");
+
+        final AxContextAlbum album = new AxContextAlbum(albumKey, "AlbumScope", false, albumSchemaKey);
+        assertNotNull(album);
+
+        final AxArtifactKey newKey = new AxArtifactKey("NewAlbumName", "0.0.1");
+        album.setKey(newKey);
+        assertEquals("NewAlbumName:0.0.1", album.getKey().getId());
+        assertEquals("NewAlbumName:0.0.1", album.getKeys().get(0).getId());
+        album.setKey(albumKey);
+
+        assertThatThrownBy(() -> album.setScope(""))
+            .hasMessage("parameter \"scope\": value \"\", does not match regular expression "
+                    + "\"[A-Za-z0-9\\-_]+\"");
+
+        album.setScope("NewAlbumScope");
+        assertEquals("NewAlbumScope", album.getScope());
+
+        assertEquals(false, album.isWritable());
+        album.setWritable(true);
+        assertEquals(true, album.isWritable());
+
+        final AxArtifactKey newSchemaKey = new AxArtifactKey("NewAlbumSchemaName", "0.0.1");
+        album.setItemSchema(newSchemaKey);
+        assertEquals("NewAlbumSchemaName:0.0.1", album.getItemSchema().getId());
+        album.setItemSchema(albumSchemaKey);
+    }
+
+    private AxContextAlbum setTestAlbum() {
+        final AxArtifactKey newKey = new AxArtifactKey("NewAlbumName", "0.0.1");
+        final AxArtifactKey newSchemaKey = new AxArtifactKey("NewAlbumSchemaName", "0.0.1");
+
+        final AxContextAlbum album = new AxContextAlbum(newKey, "AlbumScope", false, newSchemaKey);
+
+        album.setScope("NewAlbumScope");
+        album.setWritable(true);
+
+        return album;
+    }
+
+    @Test
+    public void testAxvalidationAlbum() {
+        final AxContextAlbum album = setTestAlbum();
+        AxValidationResult result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        album.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        final AxArtifactKey newKey = new AxArtifactKey("NewAlbumName", "0.0.1");
+        album.setKey(newKey);
+        result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        album.setScope("UNDEFINED");
+        result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        album.setScope("NewAlbumScope");
+        result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        album.setItemSchema(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        final AxArtifactKey albumSchemaKey = new AxArtifactKey("AlbumSchemaName", "0.0.1");
+        album.setItemSchema(albumSchemaKey);
+        result = new AxValidationResult();
+        result = album.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+    }
+
+    @Test
+    public void testEqualsAlbum() {
+        final AxContextAlbum album = setTestAlbum();
+        final AxArtifactKey newKey = new AxArtifactKey("NewAlbumName", "0.0.1");
+        final AxArtifactKey albumSchemaKey = new AxArtifactKey("AlbumSchemaName", "0.0.1");
+        album.setItemSchema(albumSchemaKey);
+
+        final AxContextAlbum clonedAlbum = new AxContextAlbum(album);
+        assertEquals("AxContextAlbum(key=AxArtifactKey:(name=NewAlbumName,version=0.0.1), "
+                        + "scope=NewAlbumScope, isWritable=true, itemSchema="
+                        + "AxArtifactKey:(name=AlbumSchemaName,version=0.0.1))", clonedAlbum.toString());
+
+        assertNotEquals(0, album.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(album, album); // NOSONAR
+        assertEquals(album, clonedAlbum);
+        assertNotNull(album);
+        assertNotEquals(album, (Object) "Hello");
+        assertNotEquals(album, new AxContextAlbum(new AxArtifactKey(), "Scope", false, AxArtifactKey.getNullKey()));
+        assertNotEquals(album, new AxContextAlbum(newKey, "Scope", false, AxArtifactKey.getNullKey()));
+        assertNotEquals(album, new AxContextAlbum(newKey, "NewAlbumScope", false, AxArtifactKey.getNullKey()));
+        assertNotEquals(album, new AxContextAlbum(newKey, "NewAlbumScope", true, AxArtifactKey.getNullKey()));
+        assertEquals(album, new AxContextAlbum(newKey, "NewAlbumScope", true, albumSchemaKey));
+
+        assertEquals(0, album.compareTo(album));
+        assertEquals(0, album.compareTo(clonedAlbum));
+        assertNotEquals(0, album.compareTo(null));
+        assertNotEquals(0, album.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, album.compareTo(
+                        new AxContextAlbum(new AxArtifactKey(), "Scope", false, AxArtifactKey.getNullKey())));
+        assertNotEquals(0, album.compareTo(new AxContextAlbum(newKey, "Scope", false, AxArtifactKey.getNullKey())));
+        assertNotEquals(0, album
+                        .compareTo(new AxContextAlbum(newKey, "NewAlbumScope", false, AxArtifactKey.getNullKey())));
+        assertNotEquals(0,
+                        album.compareTo(new AxContextAlbum(newKey, "NewAlbumScope", true, AxArtifactKey.getNullKey())));
+        assertEquals(0, album.compareTo(new AxContextAlbum(newKey, "NewAlbumScope", true, albumSchemaKey)));
+    }
+
+    @Test
+    public void testMultipleAlbums() {
+        final AxContextAlbums albums = new AxContextAlbums();
+        final AxContextAlbum album = setTestAlbum();
+        final AxArtifactKey newKey = new AxArtifactKey("NewAlbumName", "0.0.1");
+        AxValidationResult result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        // Observation, no albums in album map
+        albums.setKey(new AxArtifactKey("AlbumsKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.OBSERVATION, result.getValidationResult());
+
+        albums.getAlbumsMap().put(newKey, album);
+        result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        albums.getAlbumsMap().put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        albums.getAlbumsMap().remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        albums.getAlbumsMap().put(new AxArtifactKey("NullValueKey", "0.0.1"), null);
+        result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        albums.getAlbumsMap().remove(new AxArtifactKey("NullValueKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = albums.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+    }
+
+    @Test
+    public void testClonedAlbums() {
+        final AxContextAlbums albums = new AxContextAlbums();
+        final AxContextAlbum album = setTestAlbum();
+        final AxArtifactKey newKey = new AxArtifactKey("NewAlbumName", "0.0.1");
+        albums.setKey(new AxArtifactKey("AlbumsKey", "0.0.1"));
+        albums.getAlbumsMap().put(newKey, album);
+        albums.clean();
+
+        final AxContextAlbums clonedAlbums = new AxContextAlbums(albums);
+        assertThat(clonedAlbums.toString()).startsWith(
+                        "AxContextAlbums(key=AxArtifactKey:(name=AlbumsKey,version=0.0.1)");
+
+        assertNotEquals(0, albums.hashCode());
+
+        assertEquals(albums, clonedAlbums);
+        assertNotNull(albums);
+        assertNotEquals(albums, (Object) "Hello");
+        assertNotEquals(albums, new AxContextAlbums(new AxArtifactKey()));
+
+        assertEquals(0, albums.compareTo(albums));
+        assertEquals(0, albums.compareTo(clonedAlbums));
+        assertNotEquals(0, albums.compareTo(null));
+        assertNotEquals(0, albums.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, albums.compareTo(new AxContextAlbums(new AxArtifactKey())));
+
+        clonedAlbums.get(newKey).setScope("YetAnotherScope");
+        assertNotEquals(0, albums.compareTo(clonedAlbums));
+
+        assertEquals("NewAlbumName", albums.get("NewAlbumName").getKey().getName());
+        assertEquals("NewAlbumName", albums.get("NewAlbumName", "0.0.1").getKey().getName());
+        assertEquals(1, albums.getAll("NewAlbumName", "0.0.1").size());
+        assertEquals(0, albums.getAll("NonExistantAlbumName").size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextModelTest.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextModelTest.java
new file mode 100644
index 000000000..b148ef6be
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextModelTest.java
@@ -0,0 +1,95 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+
+/**
+ * Context model tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ContextModelTest {
+
+    @Test
+    public void test() {
+        assertNotNull(new AxContextModel());
+        assertNotNull(new AxContextModel(new AxArtifactKey()));
+        assertNotNull(new AxContextModel(new AxArtifactKey(), new AxContextSchemas(), new AxKeyInformation()));
+        assertNotNull(new AxContextModel(new AxArtifactKey(), new AxContextSchemas(), new AxContextAlbums(),
+                        new AxKeyInformation()));
+
+        final AxArtifactKey modelKey = new AxArtifactKey("ModelKey", "0.0.1");
+        final AxArtifactKey schemasKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxArtifactKey albumsKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxArtifactKey keyInfoKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxContextModel model = new AxContextModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxContextAlbums(albumsKey), new AxKeyInformation(keyInfoKey));
+        model.register();
+
+        model.clean();
+        assertNotNull(model);
+        assertThat(model.toString()).startsWith("AxContextModel(super=AxContextModel:(key=AxArtifactKey:");
+
+        final AxContextModel clonedModel = new AxContextModel(model);
+
+        assertNotEquals(0, model.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(model, model); // NOSONAR
+        assertEquals(model, clonedModel);
+        assertNotEquals(model, (Object) "Hello");
+        assertNotEquals(model, new AxContextModel(new AxArtifactKey()));
+        assertNotEquals(model, new AxContextModel(new AxArtifactKey(), new AxContextSchemas(), new AxContextAlbums(),
+                        new AxKeyInformation()));
+        assertNotEquals(model, new AxContextModel(modelKey, new AxContextSchemas(), new AxContextAlbums(),
+                        new AxKeyInformation()));
+        assertNotEquals(model, new AxContextModel(modelKey, new AxContextSchemas(), new AxContextAlbums(),
+                        new AxKeyInformation(keyInfoKey)));
+        assertNotEquals(model, new AxContextModel(modelKey, new AxContextSchemas(schemasKey), new AxContextAlbums(),
+                        new AxKeyInformation(keyInfoKey)));
+        assertEquals(model, new AxContextModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxContextAlbums(albumsKey), new AxKeyInformation(keyInfoKey)));
+
+        assertEquals(0, model.compareTo(model));
+        assertEquals(0, model.compareTo(clonedModel));
+        assertNotEquals(0, model.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, model.compareTo(new AxContextModel(new AxArtifactKey(), new AxContextSchemas(),
+                        new AxContextAlbums(), new AxKeyInformation())));
+        assertNotEquals(0, model.compareTo(new AxContextModel(modelKey, new AxContextSchemas(), new AxContextAlbums(),
+                        new AxKeyInformation())));
+        assertNotEquals(0, model.compareTo(new AxContextModel(modelKey, new AxContextSchemas(), new AxContextAlbums(),
+                        new AxKeyInformation(keyInfoKey))));
+        assertNotEquals(0, model.compareTo(new AxContextModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxContextAlbums(), new AxKeyInformation(keyInfoKey))));
+        assertEquals(0, model.compareTo(new AxContextModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxContextAlbums(albumsKey), new AxKeyInformation(keyInfoKey))));
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextSchemasTest.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextSchemasTest.java
new file mode 100644
index 000000000..52cca14bf
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/concepts/ContextSchemasTest.java
@@ -0,0 +1,229 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020-2021 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Context schema tests.
+ */
+public class ContextSchemasTest {
+
+    @Test
+    public void testNewAxContextSchema() {
+        assertNotNull(new AxContextSchema());
+        assertNotNull(new AxContextSchema(new AxArtifactKey(), "SchemaFlavour", "SchemaDefinition"));
+
+    }
+
+    @Test
+    public void testContextSchemas() {
+        final AxContextSchema schema = new AxContextSchema(new AxArtifactKey("SchemaName", "0.0.1"), "SchemaFlavour",
+                        "SchemaDefinition");
+        assertNotNull(schema);
+
+        final AxArtifactKey newKey = new AxArtifactKey("NewSchemaName", "0.0.1");
+        schema.setKey(newKey);
+        assertEquals("NewSchemaName:0.0.1", schema.getKey().getId());
+        assertEquals("NewSchemaName:0.0.1", schema.getKeys().get(0).getId());
+
+        assertThatThrownBy(() -> schema.setSchemaFlavour(""))
+            .hasMessage("parameter \"schemaFlavour\": value \"\", "
+                            + "does not match regular expression \"[A-Za-z0-9\\-_]+\"");
+        schema.setSchemaFlavour("NewSchemaFlavour");
+        assertEquals("NewSchemaFlavour", schema.getSchemaFlavour());
+
+        schema.setSchema("NewSchemaDefinition");
+        assertEquals("NewSchemaDefinition", schema.getSchema());
+    }
+
+    private AxContextSchema setTestSchema() {
+        final AxContextSchema schema = new AxContextSchema(new AxArtifactKey("SchemaName", "0.0.1"), "SchemaFlavour",
+                "SchemaDefinition");
+        final AxArtifactKey newKey = new AxArtifactKey("NewSchemaName", "0.0.1");
+        schema.setKey(newKey);
+        schema.setSchemaFlavour("NewSchemaFlavour");
+        schema.setSchema("NewSchemaDefinition");
+
+        return schema;
+    }
+
+    @Test
+    public void testAxvalidationSchema() {
+        AxContextSchema schema = setTestSchema();
+        AxValidationResult result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        schema.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        final AxArtifactKey newKey = new AxArtifactKey("NewSchemaName", "0.0.1");
+        schema.setKey(newKey);
+        result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        schema.setSchemaFlavour("UNDEFINED");
+        result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        schema.setSchemaFlavour("NewSchemaFlavour");
+        result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        schema.setSchema("");
+        result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        schema.setSchema("NewSchemaDefinition");
+        result = new AxValidationResult();
+        result = schema.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+    }
+
+    @Test
+    public void testEqualsSchema() {
+        AxContextSchema schema = setTestSchema();
+        schema.clean();
+
+        final AxContextSchema clonedSchema = new AxContextSchema(schema);
+        assertEquals("AxContextSchema(key=AxArtifactKey:(name=NewSchemaName,version=0.0.1), "
+                        + "schemaFlavour=NewSchemaFlavour, schemaDefinition=NewSchemaDefinition)",
+                        clonedSchema.toString());
+
+        assertNotEquals(0, schema.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(schema, schema); // NOSONAR
+        assertEquals(schema, clonedSchema);
+        assertNotNull(schema);
+        assertNotEquals(schema, (Object) "Hello");
+        assertNotEquals(schema, new AxContextSchema(new AxArtifactKey(), "Flavour", "Def"));
+
+        final AxArtifactKey newKey = new AxArtifactKey("NewSchemaName", "0.0.1");
+        assertNotEquals(schema, new AxContextSchema(newKey, "Flavour", "Def"));
+        assertNotEquals(schema, new AxContextSchema(newKey, "NewSchemaFlavour", "Def"));
+        assertEquals(schema, new AxContextSchema(newKey, "NewSchemaFlavour", "NewSchemaDefinition"));
+
+        assertEquals(0, schema.compareTo(schema));
+        assertEquals(0, schema.compareTo(clonedSchema));
+        assertNotEquals(0, schema.compareTo(null));
+        assertNotEquals(0, schema.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, schema.compareTo(new AxContextSchema(new AxArtifactKey(), "Flavour", "Def")));
+        assertNotEquals(0, schema.compareTo(new AxContextSchema(newKey, "Flavour", "Def")));
+        assertNotEquals(0, schema.compareTo(new AxContextSchema(newKey, "NewSchemaFlavour", "Def")));
+        assertEquals(0, schema.compareTo(new AxContextSchema(newKey, "NewSchemaFlavour", "NewSchemaDefinition")));
+    }
+
+    @Test
+    public void testMultipleSchemas() {
+        final AxContextSchemas schemas = new AxContextSchemas();
+        AxValidationResult result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        // Still invalid, no schemas in schema map
+        schemas.setKey(new AxArtifactKey("SchemasKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        AxContextSchema schema = setTestSchema();
+        final AxArtifactKey newKey = new AxArtifactKey("NewSchemaName", "0.0.1");
+        schemas.getSchemasMap().put(newKey, schema);
+        result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        schemas.getSchemasMap().put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        schemas.getSchemasMap().remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        schemas.getSchemasMap().put(new AxArtifactKey("NullValueKey", "0.0.1"), null);
+        result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        schemas.getSchemasMap().remove(new AxArtifactKey("NullValueKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = schemas.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+    }
+
+    @Test
+    public void testClonedSchemas() {
+        final AxContextSchemas schemas = new AxContextSchemas();
+        AxContextSchema schema = setTestSchema();
+        final AxArtifactKey newKey = new AxArtifactKey("NewSchemaName", "0.0.1");
+        schemas.setKey(new AxArtifactKey("SchemasKey", "0.0.1"));
+        schemas.getSchemasMap().put(newKey, schema);
+        schemas.clean();
+
+        final AxContextSchemas clonedSchemas = new AxContextSchemas(schemas);
+        assertThat(clonedSchemas.toString())
+                        .startsWith("AxContextSchemas(key=AxArtifactKey:(name=SchemasKey,version=0.0.1),");
+
+        assertNotEquals(0, schemas.hashCode());
+
+        assertEquals(schemas, clonedSchemas);
+        assertNotNull(schemas);
+        assertNotEquals(schemas, (Object) "Hello");
+        assertNotEquals(schemas, new AxContextSchemas(new AxArtifactKey()));
+
+        assertEquals(0, schemas.compareTo(schemas));
+        assertEquals(0, schemas.compareTo(clonedSchemas));
+        assertNotEquals(0, schemas.compareTo(null));
+        assertNotEquals(0, schemas.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, schemas.compareTo(new AxContextSchemas(new AxArtifactKey())));
+
+        clonedSchemas.get(newKey).setSchemaFlavour("YetAnotherFlavour");
+        assertNotEquals(0, schemas.compareTo(clonedSchemas));
+
+        assertEquals("NewSchemaName", schemas.get("NewSchemaName").getKey().getName());
+        assertEquals("NewSchemaName", schemas.get("NewSchemaName", "0.0.1").getKey().getName());
+        assertEquals(1, schemas.getAll("NewSchemaName", "0.0.1").size());
+        assertEquals(0, schemas.getAll("NonExistantSchemaName").size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/ApexContextModelTest.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/ApexContextModelTest.java
new file mode 100644
index 000000000..998469bac
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/ApexContextModelTest.java
@@ -0,0 +1,124 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.handling;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextModel;
+
+/**
+ * Apex context model tests.
+ *
+ * @author liam
+ *
+ */
+public class ApexContextModelTest {
+
+    private static final String VALID_MODEL_STRING = "***validation of model successful***";
+
+    private static final String OBSERVATION_MODEL_STRING = "\n"
+                    + "***observations noted during validation of model***\n"
+                    + "AxArtifactKey:(name=contextAlbum1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo:OBSERVATION:description is blank\n"
+                    + "********************************";
+
+    private static final String WARNING_MODEL_STRING = "\n" + "***warnings issued during validation of model***\n"
+                    + "AxArtifactKey:(name=contextAlbum1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo:WARNING:"
+                    + "UUID is a zero UUID: 00000000-0000-0000-0000-000000000000\n"
+                    + "********************************";
+
+    private static final String INVALID_MODEL_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=StringType,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema:INVALID:"
+                    + "no schemaDefinition specified, schemaDefinition may not be blank\n"
+                    + "AxArtifactKey:(name=contextAlbum0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum:INVALID:"
+                    + "scope is not defined\n" + "********************************";
+
+    private static final String INVALID_MODEL_MALSTRUCTURED_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=ContextModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=contextAlbum1,version=0.0.2)\n"
+                    + "AxArtifactKey:(name=contextAlbum1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextModel:WARNING:"
+                    + "key not found for key information entry\n" + "AxArtifactKey:(name=ContextSchemas,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas:INVALID:"
+                    + "key on schemas entry AxArtifactKey:(name=MapType,version=0.0.1) "
+                    + "does not equal entry key AxArtifactKey:(name=MapType,version=0.0.2)\n"
+                    + "AxArtifactKey:(name=contextAlbums,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums:INVALID:"
+                    + "key on context album entry key AxArtifactKey:(name=contextAlbum1,version=0.0.1) "
+                    + "does not equal context album value key AxArtifactKey:(name=contextAlbum1,version=0.0.2)\n"
+                    + "********************************";
+
+    TestApexModel<AxContextModel> testApexModel;
+
+    /**
+     * Set up tests.
+     *
+     * @throws Exception a testing exception
+     */
+    @Before
+    public void setup() throws Exception {
+        testApexModel = new TestApexModel<AxContextModel>(AxContextModel.class, new TestApexContextModelCreator());
+    }
+
+    @Test
+    public void testModelValid() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelValid();
+        assertEquals(VALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateObservation() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateObservation();
+        assertEquals(OBSERVATION_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateWarning() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateWarning();
+        assertEquals(WARNING_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateInvalidModel() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateInvalidModel();
+        assertEquals(INVALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateMalstructured() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateMalstructured();
+        assertEquals(INVALID_MODEL_MALSTRUCTURED_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelWriteReadJson() throws Exception {
+        testApexModel.testApexModelWriteReadJson();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/ContextComparisonTest.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/ContextComparisonTest.java
new file mode 100644
index 000000000..483bc3661
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/ContextComparisonTest.java
@@ -0,0 +1,189 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.handling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextModel;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.utilities.comparison.KeyedMapDifference;
+
+/**
+ * Test context comparisons.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ContextComparisonTest {
+    private AxContextModel emptyModel;
+    private AxContextModel fullModel;
+    private AxContextModel noGlobalContextModel;
+    private AxContextModel shellModel;
+    private AxContextModel singleEntryModel;
+
+    /**
+     * Set up tests.
+     */
+    @Before
+    public void getContext() {
+        final TestContextComparisonFactory factory = new TestContextComparisonFactory();
+        emptyModel = factory.getEmptyModel();
+        fullModel = factory.getFullModel();
+        noGlobalContextModel = factory.getNoGlobalContextModel();
+        shellModel = factory.getShellModel();
+        singleEntryModel = factory.getSingleEntryModel();
+    }
+
+    @Test
+    public void testEmptyEmpty() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(emptyModel.getSchemas(), emptyModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(emptyModel.getSchemas().getSchemasMap(), schemaResult.getIdenticalValues());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(emptyModel.getAlbums(), emptyModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(emptyModel.getAlbums().getAlbumsMap(), albumResult.getIdenticalValues());
+    }
+
+    @Test
+    public void testEmptyFull() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(emptyModel.getSchemas(), fullModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(fullModel.getSchemas().getSchemasMap(), schemaResult.getRightOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(emptyModel.getAlbums(), fullModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(fullModel.getAlbums().getAlbumsMap(), albumResult.getRightOnly());
+    }
+
+    @Test
+    public void testFullEmpty() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(fullModel.getSchemas(), emptyModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(fullModel.getSchemas().getSchemasMap(), schemaResult.getLeftOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(fullModel.getAlbums(), emptyModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(fullModel.getAlbums().getAlbumsMap(), albumResult.getLeftOnly());
+    }
+
+    @Test
+    public void testEmptyNoGlobalContext() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(emptyModel.getSchemas(), noGlobalContextModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(noGlobalContextModel.getSchemas().getSchemasMap(), schemaResult.getRightOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(emptyModel.getAlbums(), noGlobalContextModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(noGlobalContextModel.getAlbums().getAlbumsMap(), albumResult.getRightOnly());
+    }
+
+    @Test
+    public void testNoGlobalContextEmpty() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(noGlobalContextModel.getSchemas(), emptyModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(noGlobalContextModel.getSchemas().getSchemasMap(), schemaResult.getLeftOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(noGlobalContextModel.getAlbums(), emptyModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(noGlobalContextModel.getAlbums().getAlbumsMap(), albumResult.getLeftOnly());
+    }
+
+    @Test
+    public void testEmptyShell() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(emptyModel.getSchemas(), shellModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(shellModel.getSchemas().getSchemasMap(), schemaResult.getRightOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(emptyModel.getAlbums(), shellModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(shellModel.getAlbums().getAlbumsMap(), albumResult.getRightOnly());
+    }
+
+    @Test
+    public void testShellEmpty() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(shellModel.getSchemas(), emptyModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(shellModel.getSchemas().getSchemasMap(), schemaResult.getLeftOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(shellModel.getAlbums(), emptyModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(shellModel.getAlbums().getAlbumsMap(), albumResult.getLeftOnly());
+    }
+
+    @Test
+    public void testEmptySingleEntry() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(emptyModel.getSchemas(), singleEntryModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(singleEntryModel.getSchemas().getSchemasMap(), schemaResult.getRightOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(emptyModel.getAlbums(), singleEntryModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(singleEntryModel.getAlbums().getAlbumsMap(), albumResult.getRightOnly());
+    }
+
+    @Test
+    public void testSingleEntryEmpty() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(singleEntryModel.getSchemas(), emptyModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(singleEntryModel.getSchemas().getSchemasMap(), schemaResult.getLeftOnly());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(singleEntryModel.getAlbums(), emptyModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(singleEntryModel.getAlbums().getAlbumsMap(), albumResult.getLeftOnly());
+    }
+
+    @Test
+    public void testFullFull() {
+        final KeyedMapDifference<AxArtifactKey, AxContextSchema> schemaResult = new ContextComparer()
+                        .compare(fullModel.getSchemas(), fullModel.getSchemas());
+        assertNotNull(schemaResult);
+        assertEquals(fullModel.getSchemas().getSchemasMap(), schemaResult.getIdenticalValues());
+
+        final KeyedMapDifference<AxArtifactKey, AxContextAlbum> albumResult = new ContextComparer()
+                        .compare(fullModel.getAlbums(), fullModel.getAlbums());
+        assertNotNull(albumResult);
+        assertEquals(fullModel.getAlbums().getAlbumsMap(), albumResult.getIdenticalValues());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/TestApexContextModelCreator.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/TestApexContextModelCreator.java
new file mode 100644
index 000000000..3fe7e3aa2
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/TestApexContextModelCreator.java
@@ -0,0 +1,122 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.handling;
+
+import java.util.UUID;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextModel;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+
+public class TestApexContextModelCreator implements TestApexModelCreator<AxContextModel> {
+
+    @Override
+    public AxContextModel getModel() {
+        final AxContextSchema schema0 = new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java",
+                "org.onap.policy.apex.concept.TestContextItem000");
+        final AxContextSchema schema1 = new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java",
+                "org.onap.policy.apex.concept.TestContextItem00A");
+
+        final AxContextSchemas contextSchemas = new AxContextSchemas(new AxArtifactKey("ContextSchemas", "0.0.1"));
+        contextSchemas.getSchemasMap().put(schema0.getKey(), schema0);
+        contextSchemas.getSchemasMap().put(schema1.getKey(), schema1);
+
+        final AxContextAlbum contextAlbum0 =
+                new AxContextAlbum(new AxArtifactKey("contextAlbum0", "0.0.1"), "APPLICATION", true, schema0.getKey());
+        final AxContextAlbum contextAlbum1 =
+                new AxContextAlbum(new AxArtifactKey("contextAlbum1", "0.0.1"), "GLOBAL", false, schema1.getKey());
+
+        final AxContextAlbums axContext = new AxContextAlbums(new AxArtifactKey("contextAlbums", "0.0.1"));
+        axContext.getAlbumsMap().put(contextAlbum0.getKey(), contextAlbum0);
+        axContext.getAlbumsMap().put(contextAlbum1.getKey(), contextAlbum1);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+        final AxContextModel contextModel = new AxContextModel(new AxArtifactKey("ContextModel", "0.0.1"),
+                contextSchemas, axContext, keyInformation);
+
+        contextModel.setKeyInformation(keyInformation);
+        contextModel.getKeyInformation().getKeyInfoMap().put(schema0.getKey(), new AxKeyInfo(schema0.getKey(),
+                UUID.fromString("00000000-0000-0000-0000-000000000001"), "axContextSchema0"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(schema1.getKey(), new AxKeyInfo(schema1.getKey(),
+                UUID.fromString("00000000-0000-0000-0000-000000000002"), "axContextSchema1"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(contextSchemas.getKey(), new AxKeyInfo(
+                contextSchemas.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000003"), "ContextSchemas"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(contextAlbum0.getKey(), new AxKeyInfo(
+                contextAlbum0.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000004"), "contextAlbum0"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(contextAlbum1.getKey(), new AxKeyInfo(
+                contextAlbum1.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000005"), "contextAlbum1"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(axContext.getKey(), new AxKeyInfo(axContext.getKey(),
+                UUID.fromString("00000000-0000-0000-0000-000000000006"), "axContext"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(contextModel.getKey(), new AxKeyInfo(contextModel.getKey(),
+                UUID.fromString("00000000-0000-0000-0000-000000000007"), "contextModel"));
+        contextModel.getKeyInformation().getKeyInfoMap().put(keyInformation.getKey(), new AxKeyInfo(
+                keyInformation.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000008"), "keyInformation"));
+
+        return contextModel;
+    }
+
+    @Override
+    public AxContextModel getInvalidModel() {
+        final AxContextModel contextModel = getModel();
+
+        contextModel.getAlbums().get(new AxArtifactKey("contextAlbum0", "0.0.1")).setScope("UNDEFINED");
+
+        contextModel.getSchemas().get(new AxArtifactKey("StringType", "0.0.1")).setSchema("");
+
+        return contextModel;
+    }
+
+    @Override
+    public AxContextModel getMalstructuredModel() {
+        final AxContextModel contextModel = getModel();
+
+        contextModel.getAlbums().get(new AxArtifactKey("contextAlbum1", "0.0.1"))
+                .setKey(new AxArtifactKey("contextAlbum1", "0.0.2"));;
+        contextModel.getSchemas().get(new AxArtifactKey("MapType", "0.0.1"))
+                .setKey(new AxArtifactKey("MapType", "0.0.2"));;
+
+        return contextModel;
+    }
+
+    @Override
+    public AxContextModel getObservationModel() {
+        final AxContextModel contextModel = getModel();
+
+        contextModel.getKeyInformation().get("contextAlbum1", "0.0.1").setDescription("");
+
+        return contextModel;
+    }
+
+    @Override
+    public AxContextModel getWarningModel() {
+        final AxContextModel contextModel = getModel();
+
+        contextModel.getKeyInformation().get("contextAlbum1", "0.0.1")
+                .setUuid(UUID.fromString("00000000-0000-0000-0000-000000000000"));
+
+        return contextModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/TestContextComparisonFactory.java b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/TestContextComparisonFactory.java
new file mode 100644
index 000000000..f7c7a1345
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/contextmodel/handling/TestContextComparisonFactory.java
@@ -0,0 +1,148 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.contextmodel.handling;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextModel;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+
+/**
+ * This class creates sample Policy Models.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class TestContextComparisonFactory {
+
+    /**
+     * Get a full context model.
+     * @return the model
+     */
+    public AxContextModel getFullModel() {
+        final AxContextSchema testContextSchema000 =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema000", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema000");
+        final AxContextSchema testContextSchema00A =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema00A", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema00A");
+        final AxContextSchema testContextSchema00C =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema00C", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema00C");
+
+        final AxContextAlbum externalContextAlbum = new AxContextAlbum(
+                new AxArtifactKey("ExternalContextAlbum", "0.0.1"), "EXTERNAL", false, testContextSchema000.getKey());
+        final AxContextAlbum globalContextAlbum = new AxContextAlbum(new AxArtifactKey("GlobalContextAlbum", "0.0.1"),
+                "GLOBAL", true, testContextSchema00A.getKey());
+        final AxContextAlbum policy0ContextAlbum = new AxContextAlbum(new AxArtifactKey("Policy0ContextAlbum", "0.0.1"),
+                "APPLICATION", true, testContextSchema00C.getKey());
+        final AxContextAlbum policy1ContextAlbum = new AxContextAlbum(
+                new AxArtifactKey("Policy1ContextAlbum ", "0.0.1"), "APPLICATION", true, testContextSchema00C.getKey());
+
+        final AxContextModel contextModel = new AxContextModel(new AxArtifactKey("ContextModel", "0.0.1"));
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema000.getKey(), testContextSchema000);
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema00A.getKey(), testContextSchema00A);
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema00C.getKey(), testContextSchema00C);
+
+        contextModel.getAlbums().getAlbumsMap().put(externalContextAlbum.getKey(), externalContextAlbum);
+        contextModel.getAlbums().getAlbumsMap().put(globalContextAlbum.getKey(), globalContextAlbum);
+        contextModel.getAlbums().getAlbumsMap().put(policy0ContextAlbum.getKey(), policy0ContextAlbum);
+        contextModel.getAlbums().getAlbumsMap().put(policy1ContextAlbum.getKey(), policy1ContextAlbum);
+
+        return contextModel;
+    }
+
+    public AxContextModel getEmptyModel() {
+        return new AxContextModel(new AxArtifactKey("Context", "0.0.1"));
+    }
+
+    /**
+     * Get a skeleton model.
+     * @return The model
+     */
+    public AxContextModel getShellModel() {
+        final AxContextSchema testContextSchema000 =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema000", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema000");
+        final AxContextSchema testContextSchema00A =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema00A", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema00A");
+        final AxContextSchema testContextSchema00C =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema00C", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema00C");
+
+        final AxContextModel contextModel = new AxContextModel(new AxArtifactKey("ContextModel", "0.0.1"));
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema000.getKey(), testContextSchema000);
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema00A.getKey(), testContextSchema00A);
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema00C.getKey(), testContextSchema00C);
+
+        return contextModel;
+    }
+
+    /**
+     * Get a single entry model.
+     * @return The single entry model
+     */
+    public AxContextModel getSingleEntryModel() {
+        final AxContextSchema testContextSchema000 =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema000", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema000");
+
+        final AxContextAlbum policy1ContextAlbum = new AxContextAlbum(
+                new AxArtifactKey("Policy1ContextAlbum ", "0.0.1"), "APPLICATION", true, testContextSchema000.getKey());
+
+        final AxContextModel contextModel = new AxContextModel(new AxArtifactKey("ContextModel", "0.0.1"));
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema000.getKey(), testContextSchema000);
+
+        contextModel.getAlbums().getAlbumsMap().put(policy1ContextAlbum.getKey(), policy1ContextAlbum);
+
+        return contextModel;
+    }
+
+    /**
+     * Get a model with no global entries.
+     * @return the model
+     */
+    public AxContextModel getNoGlobalContextModel() {
+        final AxContextSchema testContextSchema000 =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema000", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema000");
+        final AxContextSchema testContextSchema00C =
+                new AxContextSchema(new AxArtifactKey("TestContextSchema00C", "0.0.1"), "JAVA",
+                        "org.onap.policy.apex.concept.TestContextSchema00C");
+
+        final AxContextAlbum externalContextAlbum = new AxContextAlbum(
+                new AxArtifactKey("ExternalContextAlbum", "0.0.1"), "EXTERNAL", false, testContextSchema000.getKey());
+        final AxContextAlbum policy0ContextAlbum = new AxContextAlbum(new AxArtifactKey("Policy0ContextAlbum", "0.0.1"),
+                "APPLICATION", true, testContextSchema00C.getKey());
+        final AxContextAlbum policy1ContextAlbum = new AxContextAlbum(
+                new AxArtifactKey("Policy1ContextAlbum ", "0.0.1"), "APPLICATION", true, testContextSchema00C.getKey());
+
+        final AxContextModel contextModel = new AxContextModel(new AxArtifactKey("ContextModel", "0.0.1"));
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema000.getKey(), testContextSchema000);
+        contextModel.getSchemas().getSchemasMap().put(testContextSchema00C.getKey(), testContextSchema00C);
+
+        contextModel.getAlbums().getAlbumsMap().put(externalContextAlbum.getKey(), externalContextAlbum);
+        contextModel.getAlbums().getAlbumsMap().put(policy0ContextAlbum.getKey(), policy0ContextAlbum);
+        contextModel.getAlbums().getAlbumsMap().put(policy1ContextAlbum.getKey(), policy1ContextAlbum);
+
+        return contextModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/enginemodel/concepts/EngineModelTest.java b/model/src/test/java/org/onap/policy/apex/model/enginemodel/concepts/EngineModelTest.java
new file mode 100644
index 000000000..c23687bb1
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/enginemodel/concepts/EngineModelTest.java
@@ -0,0 +1,176 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.enginemodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+
+/**
+ * Test engine models.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EngineModelTest {
+
+    @Test
+    public void testEnginetModel() {
+        assertNotNull(new AxEngineModel());
+        assertNotNull(new AxEngineModel(new AxArtifactKey()));
+        assertNotNull(new AxEngineModel(new AxArtifactKey(), new AxContextSchemas(), new AxKeyInformation(),
+                new AxContextAlbums()));
+        assertNotNull(new AxEngineModel(new AxArtifactKey(), new AxContextSchemas(), new AxKeyInformation(),
+                new AxContextAlbums(), AxEngineState.UNDEFINED, new AxEngineStats()));
+
+        final AxArtifactKey modelKey = new AxArtifactKey("ModelName", "0.0.1");
+        final AxArtifactKey schemasKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxArtifactKey albumKey = new AxArtifactKey("AlbumKey", "0.0.1");
+        final AxArtifactKey keyInfoKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxEngineStats stats = new AxEngineStats(new AxReferenceKey(modelKey, "EngineStats"));
+        final AxEngineStats otherStats = new AxEngineStats();
+        otherStats.setAverageExecutionTime(100);
+
+        final AxEngineModel model = new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats);
+        model.register();
+
+        assertThatThrownBy(() -> model.setKey(null))
+            .hasMessage("key may not be null");
+        model.setKey(modelKey);
+        assertEquals("ModelName:0.0.1", model.getKey().getId());
+        assertEquals("ModelName:0.0.1", model.getKeys().get(0).getId());
+
+        final long timestamp = System.currentTimeMillis();
+        model.setTimestamp(timestamp);
+        assertEquals(timestamp, model.getTimestamp());
+        model.setTimestamp(-1);
+        assertTrue(model.getTimeStampString().matches("\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}.\\d{3}"));
+
+        assertThatThrownBy(() -> model.setState(null))
+            .hasMessage("state may not be null");
+        for (final AxEngineState state : AxEngineState.values()) {
+            model.setState(state);
+            assertEquals(state, model.getState());
+        }
+
+        model.setState(AxEngineState.READY);
+        assertEquals(AxEngineState.READY, model.getState());
+
+        assertThatThrownBy(() -> model.setStats(null))
+            .hasMessage("stats may not be null");
+        model.setStats(stats);
+        assertEquals(stats, model.getStats());
+
+        model.clean();
+        assertNotNull(model);
+        assertThat(model.toString()).startsWith("AxEngineModel:(AxContextModel(super=AxEngineModel:(key=A");
+
+        final AxEngineModel clonedModel = new AxEngineModel(model);
+
+        assertNotEquals(0, model.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(model, model); // NOSONAR
+        assertEquals(model, clonedModel);
+        assertNotEquals(model, (Object) "Hello");
+        assertNotEquals(model, new AxEngineModel(new AxArtifactKey()));
+        assertNotEquals(model, new AxEngineModel(new AxArtifactKey(), new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats));
+        assertNotEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(), new AxKeyInformation(keyInfoKey),
+                new AxContextAlbums(albumKey), AxEngineState.READY, stats));
+        assertNotEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(schemasKey), new AxKeyInformation(),
+                new AxContextAlbums(albumKey), AxEngineState.READY, stats));
+        assertNotEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(), AxEngineState.READY, stats));
+        assertNotEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.STOPPED, stats));
+        assertNotEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, otherStats));
+        model.setTimestamp(timestamp);
+        assertNotEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats));
+        model.setTimestamp(0);
+        assertEquals(model, new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats));
+
+        model.setTimestamp(-1);
+        assertEquals(0, model.compareTo(model));
+        assertEquals(0, model.compareTo(clonedModel));
+        assertNotEquals(0, model.compareTo(new AxArtifactKey()));
+        assertNotEquals(model, new AxEngineModel(new AxArtifactKey()));
+        assertNotEquals(0, model.compareTo(new AxEngineModel(new AxArtifactKey(), new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats)));
+        assertNotEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats)));
+        assertNotEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(), new AxContextAlbums(albumKey), AxEngineState.READY, stats)));
+        assertNotEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(), AxEngineState.READY, stats)));
+        assertNotEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.STOPPED, stats)));
+        assertNotEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, otherStats)));
+        model.setTimestamp(timestamp);
+        assertNotEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats)));
+        model.setTimestamp(0);
+        assertEquals(0, model.compareTo(new AxEngineModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxContextAlbums(albumKey), AxEngineState.READY, stats)));
+
+        model.setTimestamp(timestamp);
+        AxValidationResult result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        model.setTimestamp(-1);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.setTimestamp(timestamp);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        model.setState(AxEngineState.UNDEFINED);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.setState(AxEngineState.READY);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/enginemodel/concepts/EngineStatsTest.java b/model/src/test/java/org/onap/policy/apex/model/enginemodel/concepts/EngineStatsTest.java
new file mode 100644
index 000000000..3eca27c08
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/enginemodel/concepts/EngineStatsTest.java
@@ -0,0 +1,267 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2022 Bell Canada.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.enginemodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import io.prometheus.client.CollectorRegistry;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test the engine statistics.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EngineStatsTest {
+    private static final Object WAIT_LOCK = new Object();
+    private static final String ENGINE_KEY = "EngineKey";
+    private static final String ENGINE_VERSION = "0.0.1";
+
+    @Test
+    public void testEngineStats() {
+        assertNotNull(new AxEngineStats());
+        assertNotNull(new AxEngineStats(new AxReferenceKey()));
+
+        final AxReferenceKey statsKey = new AxReferenceKey(ENGINE_KEY, ENGINE_VERSION, "EngineStats");
+        final AxEngineStats stats = new AxEngineStats(statsKey);
+
+        assertThatThrownBy(() -> stats.setKey(null))
+            .hasMessage("key may not be null");
+        stats.setKey(statsKey);
+        assertEquals("EngineKey:0.0.1:NULL:EngineStats", stats.getKey().getId());
+        assertEquals("EngineKey:0.0.1:NULL:EngineStats", stats.getKeys().get(0).getId());
+
+        stats.setAverageExecutionTime(123.45);
+        assertEquals(Double.valueOf(123.45), Double.valueOf(stats.getAverageExecutionTime()));
+        checkAvgExecTimeMetric(stats);
+
+        stats.setEventCount(987);
+        assertEquals(987, stats.getEventCount());
+        checkEventsCountMetric(stats);
+
+        final long lastExecutionTime = System.currentTimeMillis();
+        stats.setLastExecutionTime(lastExecutionTime);
+        assertEquals(lastExecutionTime, stats.getLastExecutionTime());
+        checkLastExecTimeMetric(stats);
+
+        final long timestamp = System.currentTimeMillis();
+        stats.setTimeStamp(timestamp);
+        assertEquals(timestamp, stats.getTimeStamp());
+        assertNotNull(stats.getTimeStampString());
+
+        final long upTime = System.currentTimeMillis() - timestamp;
+        stats.setUpTime(upTime);
+        assertEquals(upTime, stats.getUpTime());
+        checkUpTimeMetric(stats);
+
+        stats.engineStart();
+        assertTrue(stats.getUpTime() > -1);
+        checkEngineStartTimestampMetric(stats);
+        checkLastExecTimeMetric(stats);
+        stats.engineStop();
+        assertTrue(stats.getUpTime() >= 0);
+
+        stats.engineStop();
+        checkUpTimeMetric(stats);
+        checkEngineStartTimestampMetric(stats);
+
+        stats.reset();
+
+        stats.setEventCount(-2);
+        stats.executionEnter(new AxArtifactKey());
+        assertEquals(2, stats.getEventCount());
+        checkEventsCountMetric(stats);
+
+        stats.setEventCount(10);
+        stats.executionEnter(new AxArtifactKey());
+        assertEquals(11, stats.getEventCount());
+        checkEventsCountMetric(stats);
+
+        stats.reset();
+        stats.engineStart();
+        stats.setEventCount(4);
+        checkUpTimeMetric(stats);
+        stats.executionEnter(new AxArtifactKey());
+        checkEventsCountMetric(stats);
+        checkAvgExecTimeMetric(stats);
+        checkEngineStartTimestampMetric(stats);
+
+        synchronized (WAIT_LOCK) {
+            try {
+                WAIT_LOCK.wait(10);
+            } catch (InterruptedException e) {
+                fail("test should not throw an exception");
+            }
+        }
+
+        stats.executionExit();
+        final double avExecutionTime = stats.getAverageExecutionTime();
+        assertTrue(avExecutionTime >= 2.0 && avExecutionTime < 10.0);
+        stats.engineStop();
+        checkUpTimeMetric(stats);
+
+        AxValidationResult result = new AxValidationResult();
+        result = stats.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        stats.setKey(new AxReferenceKey());
+        result = new AxValidationResult();
+        result = stats.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        stats.setKey(statsKey);
+        result = new AxValidationResult();
+        result = stats.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        stats.clean();
+        stats.reset();
+        checkAllPrometheusMetrics(stats);
+
+        final AxEngineStats clonedStats = new AxEngineStats(stats);
+        assertEquals("AxEngineStats:(engineKey=AxReferenceKey:(parentKey", clonedStats.toString().substring(0, 50));
+
+        assertNotNull(stats.getKeys());
+
+        assertNotEquals(0, stats.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(stats, stats); // NOSONAR
+        assertEquals(stats, clonedStats);
+        assertNotNull(stats);
+        checkAllPrometheusMetrics(clonedStats);
+
+        Object helloObject = "Hello";
+        assertNotEquals(stats, helloObject);
+        assertNotEquals(stats, new AxEngineStats(new AxReferenceKey()));
+
+        assertEquals(0, stats.compareTo(stats));
+        assertEquals(0, stats.compareTo(clonedStats));
+        assertNotEquals(0, stats.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, stats.compareTo(null));
+        assertNotEquals(0, stats.compareTo(new AxEngineStats(new AxReferenceKey())));
+
+        stats.setTimeStamp(1);
+        assertNotEquals(stats, new AxEngineStats(statsKey));
+        assertNotEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        stats.setTimeStamp(0);
+        assertEquals(stats, new AxEngineStats(statsKey));
+        assertEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        checkAllPrometheusMetrics(clonedStats);
+
+        stats.setEventCount(1);
+        assertNotEquals(stats, new AxEngineStats(statsKey));
+        assertNotEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        stats.setEventCount(0);
+        assertEquals(stats, new AxEngineStats(statsKey));
+        assertEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+
+        stats.setLastExecutionTime(1);
+        assertNotEquals(stats, new AxEngineStats(statsKey));
+        assertNotEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        stats.setLastExecutionTime(0);
+        assertEquals(stats, new AxEngineStats(statsKey));
+        assertEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+
+        stats.setAverageExecutionTime(1);
+        assertNotEquals(stats, new AxEngineStats(statsKey));
+        assertNotEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        stats.setAverageExecutionTime(0);
+        assertEquals(stats, new AxEngineStats(statsKey));
+        assertEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+
+        stats.setUpTime(1);
+        assertNotEquals(stats, new AxEngineStats(statsKey));
+        assertNotEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        stats.setUpTime(0);
+        assertEquals(stats, new AxEngineStats(statsKey));
+        assertEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+
+        assertEquals(-1, stats.compareTo(new AxEngineStats(statsKey, 0, 0, 0, 0.0, 0, 1)));
+
+        stats.engineStart();
+        assertNotEquals(stats, new AxEngineStats(statsKey));
+        final AxEngineStats newStats = new AxEngineStats(statsKey);
+        newStats.setTimeStamp(stats.getTimeStamp());
+        assertNotEquals(stats, newStats);
+        assertNotEquals(0, stats.compareTo(newStats));
+        stats.engineStop();
+        checkUpTimeMetric(stats);
+        checkEngineStartTimestampMetric(stats);
+        stats.reset();
+        assertEquals(stats, new AxEngineStats(statsKey));
+        assertEquals(0, stats.compareTo(new AxEngineStats(statsKey)));
+        checkAllPrometheusMetrics(stats);
+    }
+
+    private void checkUpTimeMetric(AxEngineStats stats) {
+        Double upTimeMetric = CollectorRegistry.defaultRegistry.getSampleValue("pdpa_engine_uptime",
+            new String[]{AxEngineStats.ENGINE_INSTANCE_ID}, new String[]{ENGINE_KEY + ":" + ENGINE_VERSION}) * 1000d;
+        assertEquals(upTimeMetric.longValue(), stats.getUpTime());
+    }
+
+    private void checkEventsCountMetric(AxEngineStats stats) {
+        Double eventsCountMetric = CollectorRegistry.defaultRegistry.getSampleValue("pdpa_engine_event_executions",
+                new String[]{AxEngineStats.ENGINE_INSTANCE_ID}, new String[]{ENGINE_KEY + ":" + ENGINE_VERSION});
+        assertEquals(eventsCountMetric.longValue(), stats.getEventCount());
+    }
+
+    private void checkLastExecTimeMetric(AxEngineStats stats) {
+        Double lastExecTimeMetric = CollectorRegistry.defaultRegistry
+            .getSampleValue("pdpa_engine_last_execution_time_sum", new String[]{AxEngineStats.ENGINE_INSTANCE_ID},
+                new String[]{ENGINE_KEY + ":" + ENGINE_VERSION}) * 1000d;
+        assertEquals(lastExecTimeMetric.longValue(), stats.getLastExecutionTime());
+    }
+
+    private void checkEngineStartTimestampMetric(AxEngineStats stats) {
+        Double engineStartTimestampMetric = CollectorRegistry.defaultRegistry
+            .getSampleValue("pdpa_engine_last_start_timestamp_epoch",
+                new String[]{AxEngineStats.ENGINE_INSTANCE_ID}, new String[]{ENGINE_KEY + ":" + ENGINE_VERSION});
+        assertEquals(engineStartTimestampMetric.longValue(), stats.getLastStart());
+    }
+
+    private void checkAvgExecTimeMetric(AxEngineStats stats) {
+        Double avgExecTimeMetric = CollectorRegistry.defaultRegistry
+            .getSampleValue("pdpa_engine_average_execution_time_seconds",
+                new String[]{AxEngineStats.ENGINE_INSTANCE_ID},
+                new String[]{ENGINE_KEY + ":" + ENGINE_VERSION}) * 1000d;
+        assertEquals(avgExecTimeMetric, Double.valueOf(stats.getAverageExecutionTime()));
+    }
+
+    private void checkAllPrometheusMetrics(AxEngineStats stats) {
+        checkEventsCountMetric(stats);
+        checkUpTimeMetric(stats);
+        checkAvgExecTimeMetric(stats);
+        checkEngineStartTimestampMetric(stats);
+        checkEngineStartTimestampMetric(stats);
+    }
+}
\ No newline at end of file
diff --git a/model/src/test/java/org/onap/policy/apex/model/enginemodel/handling/ApexEngineModelTest.java b/model/src/test/java/org/onap/policy/apex/model/enginemodel/handling/ApexEngineModelTest.java
new file mode 100644
index 000000000..e7fdd2d93
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/enginemodel/handling/ApexEngineModelTest.java
@@ -0,0 +1,81 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.enginemodel.handling;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+import org.onap.policy.apex.model.enginemodel.concepts.AxEngineModel;
+
+public class ApexEngineModelTest {
+    private static final String VALID_MODEL_STRING = "***validation of model successful***";
+
+    private static final String INVALID_MODEL_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=AnEngine,version=0.0.1):"
+                    + "org.onap.policy.apex.model.enginemodel.concepts.AxEngineModel:INVALID:"
+                    + "AxEngineModel - state is UNDEFINED\n" + "********************************";
+
+    private static final String INVALID_MODEL_MALSTRUCTURED_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=AnEngine,version=0.0.1):"
+                    + "org.onap.policy.apex.model.enginemodel.concepts.AxEngineModel:INVALID:"
+                    + "AxEngineModel - timestamp is not set\n" + "AxArtifactKey:(name=AnEngine,version=0.0.1):"
+                    + "org.onap.policy.apex.model.enginemodel.concepts.AxEngineModel:INVALID:"
+                    + "AxEngineModel - state is UNDEFINED\n" + "********************************";
+
+    TestApexModel<AxEngineModel> testApexModel;
+
+    /**
+     * Set up the test.
+     *
+     * @throws Exception errors from test setup
+     */
+    @Before
+    public void setup() throws Exception {
+        testApexModel = new TestApexModel<AxEngineModel>(AxEngineModel.class, new DummyTestApexEngineModelCreator());
+    }
+
+    @Test
+    public void testModelValid() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelValid();
+        assertEquals(VALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateInvalidModel() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateInvalidModel();
+        assertEquals(INVALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateMalstructured() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateMalstructured();
+        assertEquals(INVALID_MODEL_MALSTRUCTURED_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelWriteReadJson() throws Exception {
+        testApexModel.testApexModelWriteReadJson();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/enginemodel/handling/DummyTestApexEngineModelCreator.java b/model/src/test/java/org/onap/policy/apex/model/enginemodel/handling/DummyTestApexEngineModelCreator.java
new file mode 100644
index 000000000..9e7d99b72
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/enginemodel/handling/DummyTestApexEngineModelCreator.java
@@ -0,0 +1,129 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.enginemodel.handling;
+
+import java.util.UUID;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.apex.model.enginemodel.concepts.AxEngineModel;
+import org.onap.policy.apex.model.enginemodel.concepts.AxEngineState;
+import org.onap.policy.apex.model.enginemodel.concepts.AxEngineStats;
+
+public class DummyTestApexEngineModelCreator implements TestApexModelCreator<AxEngineModel> {
+
+    @Override
+    public AxEngineModel getModel() {
+        final AxContextSchema schema0 = new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.enginemodel.concepts.TestContextItem000");
+        final AxContextSchema schema1 = new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.enginemodel.concepts.TestContextItem00A");
+
+        final AxContextSchemas schemas = new AxContextSchemas(new AxArtifactKey("ContextSchemas", "0.0.1"));
+        schemas.getSchemasMap().put(schema0.getKey(), schema0);
+        schemas.getSchemasMap().put(schema1.getKey(), schema1);
+
+        final AxContextAlbum album0 =
+                new AxContextAlbum(new AxArtifactKey("contextAlbum0", "0.0.1"), "APPLICATION", true, schema1.getKey());
+
+        final AxContextAlbums albums = new AxContextAlbums(new AxArtifactKey("context", "0.0.1"));
+        albums.getAlbumsMap().put(album0.getKey(), album0);
+
+        final AxEngineModel engineModel = new AxEngineModel(new AxArtifactKey("AnEngine", "0.0.1"));
+        engineModel.setSchemas(schemas);
+        engineModel.setAlbums(albums);
+        engineModel.setTimestamp(System.currentTimeMillis());
+        engineModel.setState(AxEngineState.EXECUTING);
+        engineModel.setStats(new AxEngineStats(new AxReferenceKey(engineModel.getKey(), "EngineStats"),
+                System.currentTimeMillis(), 100, 205, 200, 12345, 9876));
+        engineModel.getKeyInformation().generateKeyInfo(engineModel);
+
+        final AxValidationResult result = new AxValidationResult();
+        engineModel.validate(result);
+
+        return engineModel;
+    }
+
+    @Override
+    public AxEngineModel getInvalidModel() {
+        final AxEngineModel engineModel = getModel();
+
+        engineModel.setTimestamp(System.currentTimeMillis());
+        engineModel.setState(AxEngineState.UNDEFINED);
+        engineModel.setStats(new AxEngineStats(new AxReferenceKey(engineModel.getKey(), "EngineStats"),
+                System.currentTimeMillis(), 100, 205, 200, 12345, 9876));
+        engineModel.getKeyInformation().generateKeyInfo(engineModel);
+
+        return engineModel;
+    }
+
+    /**
+     * Get a malstructured model.
+     */
+    public AxEngineModel getMalstructuredModel() {
+        final AxEngineModel engineModel = getModel();
+
+        engineModel.setTimestamp(-1);
+        engineModel.setState(AxEngineState.UNDEFINED);
+
+        return engineModel;
+    }
+
+    @Override
+    public AxEngineModel getObservationModel() {
+        final AxEngineModel engineModel = getModel();
+
+        final AxContextSchema schema0 = new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.enginemodel.concepts.TestContextItem000");
+        final AxContextSchema schema1 = new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.enginemodel.concepts.TestContextItem00A");
+
+        engineModel.getKeyInformation().getKeyInfoMap().put(schema0.getKey(),
+                new AxKeyInfo(schema0.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000001"), ""));
+        engineModel.getKeyInformation().getKeyInfoMap().put(schema1.getKey(),
+                new AxKeyInfo(schema1.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000002"), ""));
+
+        return engineModel;
+    }
+
+    @Override
+    public AxEngineModel getWarningModel() {
+        final AxEngineModel engineModel = getModel();
+
+        final AxContextSchema schema0 = new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.enginemodel.concepts.TestContextItem000");
+        final AxContextSchema schema1 = new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.enginemodel.concepts.TestContextItem00A");
+
+        engineModel.getKeyInformation().getKeyInfoMap().put(schema0.getKey(),
+                new AxKeyInfo(schema0.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000000"), ""));
+        engineModel.getKeyInformation().getKeyInfoMap().put(schema1.getKey(),
+                new AxKeyInfo(schema1.getKey(), UUID.fromString("00000000-0000-0000-0000-000000000001"), ""));
+
+        return engineModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/EventModelTest.java b/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/EventModelTest.java
new file mode 100644
index 000000000..cdc5fecf6
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/EventModelTest.java
@@ -0,0 +1,87 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.eventmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+
+/**
+ * Test event models.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EventModelTest {
+
+    @Test
+    public void testEventModel() {
+        assertNotNull(new AxEventModel());
+        assertNotNull(new AxEventModel(new AxArtifactKey()));
+        assertNotNull(
+                new AxEventModel(new AxArtifactKey(), new AxContextSchemas(), new AxKeyInformation(), new AxEvents()));
+
+        final AxArtifactKey modelKey = new AxArtifactKey("ModelKey", "0.0.1");
+        final AxArtifactKey schemasKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxArtifactKey eventsKey = new AxArtifactKey("EventsKey", "0.0.1");
+        final AxArtifactKey keyInfoKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxEventModel model = new AxEventModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey));
+        model.register();
+
+        model.clean();
+        assertNotNull(model);
+        assertEquals("AxEventModel:(AxEventModel:(key=AxArtifactKey:(nam", model.toString().substring(0, 50));
+
+        final AxEventModel clonedModel = new AxEventModel(model);
+
+        assertNotEquals(0, model.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(model, model); // NOSONAR
+        assertEquals(model, clonedModel);
+        assertNotEquals(model, (Object) "Hello");
+        assertNotEquals(model, new AxEventModel(new AxArtifactKey()));
+        assertNotEquals(model, new AxEventModel(modelKey, new AxContextSchemas(), new AxKeyInformation(keyInfoKey),
+                new AxEvents(eventsKey)));
+        assertNotEquals(model, new AxEventModel(modelKey, new AxContextSchemas(schemasKey), new AxKeyInformation(),
+                new AxEvents(eventsKey)));
+        assertNotEquals(model, new AxEventModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxEvents()));
+        assertEquals(model, new AxEventModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey)));
+
+        assertEquals(0, model.compareTo(model));
+        assertEquals(0, model.compareTo(clonedModel));
+        assertNotEquals(0, model.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, model.compareTo(new AxEventModel(modelKey, new AxContextSchemas(),
+                new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey))));
+        assertNotEquals(0, model.compareTo(new AxEventModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(), new AxEvents(eventsKey))));
+        assertNotEquals(0, model.compareTo(new AxEventModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxEvents())));
+        assertEquals(0, model.compareTo(new AxEventModel(modelKey, new AxContextSchemas(schemasKey),
+                new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey))));
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/EventsTest.java b/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/EventsTest.java
new file mode 100644
index 000000000..7062fcb3c
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/EventsTest.java
@@ -0,0 +1,323 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020,2022 Nordix Foundation.
+ *  Modifications Copyright (C) 2022 Bell Canada.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.eventmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.util.TreeMap;
+import java.util.TreeSet;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxToscaPolicyProcessingStatus;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test events.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EventsTest {
+
+    @Test
+    public void testEvents() {
+        final TreeMap<String, AxField> parameterMap = new TreeMap<>();
+        final TreeMap<String, AxField> parameterMapEmpty = new TreeMap<>();
+
+        assertNotNull(new AxEvent());
+        assertNotNull(new AxEvent(new AxArtifactKey()));
+        assertNotNull(new AxEvent(new AxArtifactKey(), "namespace"));
+        assertNotNull(new AxEvent(new AxArtifactKey(), "namespace", "source", "target"));
+        assertNotNull(new AxEvent(new AxArtifactKey(), "namespace", "source", "target"));
+        assertNotNull(new AxEvent(new AxArtifactKey(), "namespace", "source", "target", parameterMap, ""));
+
+        final AxEvent event = new AxEvent();
+
+        final AxArtifactKey eventKey = new AxArtifactKey("EventName", "0.0.1");
+        event.setKey(eventKey);
+        assertEquals("EventName:0.0.1", event.getKey().getId());
+        assertEquals("EventName:0.0.1", event.getKeys().get(0).getId());
+
+        event.setNameSpace("namespace");
+        assertEquals("namespace", event.getNameSpace());
+
+        event.setSource("source");
+        assertEquals("source", event.getSource());
+
+        event.setTarget("target");
+        assertEquals("target", event.getTarget());
+
+        event.setParameterMap(parameterMap);
+        assertEquals(0, event.getParameterMap().size());
+
+        event.setToscaPolicyState(AxToscaPolicyProcessingStatus.ENTRY.name());
+        assertEquals(AxToscaPolicyProcessingStatus.ENTRY.name(), event.getToscaPolicyState());
+
+        final AxField eventField =
+            new AxField(new AxReferenceKey(eventKey, "Field0"), new AxArtifactKey("Field0Schema", "0.0.1"));
+        event.getParameterMap().put(eventField.getKey().getLocalName(), eventField);
+        assertEquals(1, event.getParameterMap().size());
+
+        final AxField eventFieldBadParent =
+            new AxField(new AxReferenceKey(new AxArtifactKey("OtherEvent", "0.0.01"), "Field0"),
+                new AxArtifactKey("Field0Schema", "0.0.1"));
+
+        final AxArtifactKey newEventKey = new AxArtifactKey("NewEventName", "0.0.1");
+        event.setKey(newEventKey);
+        assertEquals("NewEventName:0.0.1", event.getKey().getId());
+        assertEquals("NewEventName:0.0.1", event.getKeys().get(0).getId());
+        assertEquals("NewEventName:0.0.1",
+            event.getParameterMap().get("Field0").getKey().getParentArtifactKey().getId());
+        event.setKey(eventKey);
+        assertEquals("EventName:0.0.1", event.getKey().getId());
+        assertEquals("EventName:0.0.1", event.getKeys().get(0).getId());
+
+        assertTrue("Field0", event.getFields().contains(eventField));
+        assertTrue(event.hasFields(new TreeSet<AxField>(parameterMap.values())));
+
+        AxValidationResult result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        event.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        event.setKey(eventKey);
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.setNameSpace("");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.WARNING, result.getValidationResult());
+
+        event.setNameSpace("namespace");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.setSource("");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.OBSERVATION, result.getValidationResult());
+
+        event.setSource("source");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.setTarget("");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.OBSERVATION, result.getValidationResult());
+
+        event.setTarget("target");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.getParameterMap().put(AxKey.NULL_KEY_NAME, null);
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        event.getParameterMap().remove(AxKey.NULL_KEY_NAME);
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.getParameterMap().put("NullField", null);
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        event.getParameterMap().remove("NullField");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.getParameterMap().put("NullField", eventField);
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        event.getParameterMap().remove("NullField");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.getParameterMap().put("BadParent", eventFieldBadParent);
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        event.getParameterMap().remove("BadParent");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        event.setToscaPolicyState("invalid_enum");
+        result = new AxValidationResult();
+        result = event.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+        event.setToscaPolicyState(AxToscaPolicyProcessingStatus.ENTRY.name());
+
+        event.clean();
+        event.buildReferences();
+        assertNotEquals(AxKey.NULL_KEY_NAME,
+            event.getParameterMap().values().iterator().next().getKey().getParentKeyName());
+
+        final AxEvent clonedEvent = new AxEvent(event);
+        assertEquals("AxEvent:(key=AxArtifactKey:(name=EventName,version=0.0.1),nameSpace=namespace",
+            clonedEvent.toString().substring(0, 77));
+
+        assertNotEquals(0, event.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(event, event); // NOSONAR
+        assertEquals(event, clonedEvent);
+        assertNotNull(event);
+
+        Object helloObj = "Hello";
+        assertNotEquals(event, helloObj);
+        assertNotEquals(event, new AxEvent(AxArtifactKey.getNullKey(), "namespace", "source", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name()));
+        assertNotEquals(event, new AxEvent(eventKey, "namespace1", "source", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name()));
+        assertNotEquals(event, new AxEvent(eventKey, "namespace", "source2", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name()));
+        assertNotEquals(event, new AxEvent(eventKey, "namespace", "source", "target3", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name()));
+        assertNotEquals(event, new AxEvent(eventKey, "namespace", "source", "target", parameterMapEmpty,
+            AxToscaPolicyProcessingStatus.ENTRY.name()));
+        assertEquals(event, new AxEvent(eventKey, "namespace", "source", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name()));
+
+        assertEquals(0, event.compareTo(event));
+        assertEquals(0, event.compareTo(clonedEvent));
+        assertNotEquals(0, event.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, event.compareTo(null));
+        assertNotEquals(0, event.compareTo(new AxEvent(AxArtifactKey.getNullKey(), "namespace", "source", "target",
+            parameterMap, AxToscaPolicyProcessingStatus.ENTRY.name())));
+        assertNotEquals(0, event.compareTo(new AxEvent(eventKey, "namespace1", "source", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name())));
+        assertNotEquals(0, event.compareTo(new AxEvent(eventKey, "namespace", "source2", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name())));
+        assertNotEquals(0, event.compareTo(new AxEvent(eventKey, "namespace", "source", "target3", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name())));
+        assertNotEquals(0, event.compareTo(new AxEvent(eventKey, "namespace", "source", "target", parameterMapEmpty,
+            AxToscaPolicyProcessingStatus.ENTRY.name())));
+        assertEquals(0, event.compareTo(new AxEvent(eventKey, "namespace", "source", "target", parameterMap,
+            AxToscaPolicyProcessingStatus.ENTRY.name())));
+
+        assertNotNull(event.getKeys());
+
+        final AxEvents events = new AxEvents();
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        // Invalid, no events in event map
+        events.setKey(new AxArtifactKey("EventsKey", "0.0.1"));
+        assertEquals("EventsKey:0.0.1", events.getKey().getId());
+
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        events.getEventMap().put(eventKey, event);
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        events.getEventMap().put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        events.getEventMap().remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        events.getEventMap().put(new AxArtifactKey("NullValueKey", "0.0.1"), null);
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        events.getEventMap().remove(new AxArtifactKey("NullValueKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        events.getEventMap().put(new AxArtifactKey("BadEventKey", "0.0.1"), event);
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        events.getEventMap().remove(new AxArtifactKey("BadEventKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = events.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        events.clean();
+        event.buildReferences();
+        assertNotEquals(AxKey.NULL_KEY_NAME,
+            event.getParameterMap().values().iterator().next().getKey().getParentKeyName());
+
+        final AxEvents clonedEvents = new AxEvents(events);
+        assertEquals("AxEvents:(key=AxArtifactKey:(name=EventsKey,version=0.0.1),e",
+            clonedEvents.toString().substring(0, 60));
+
+        assertNotEquals(0, events.hashCode());
+
+        assertEquals(events, clonedEvents);
+        assertNotNull(events);
+        assertNotEquals(event, helloObj);
+        assertNotEquals(events, new AxEvents(new AxArtifactKey()));
+
+        assertEquals(0, events.compareTo(events));
+        assertEquals(0, events.compareTo(clonedEvents));
+        assertNotEquals(0, events.compareTo(null));
+        assertNotEquals(0, events.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, events.compareTo(new AxEvents(new AxArtifactKey())));
+
+        clonedEvents.get(eventKey).setSource("AnotherSource");
+        assertNotEquals(0, events.compareTo(clonedEvents));
+
+        assertEquals(events.getKey(), events.getKeys().get(0));
+
+        assertEquals("EventName", events.get("EventName").getKey().getName());
+        assertEquals("EventName", events.get("EventName", "0.0.1").getKey().getName());
+        assertEquals(1, events.getAll("EventName", "0.0.1").size());
+        assertEquals(0, events.getAll("NonExistantEventsName").size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/FieldTest.java b/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/FieldTest.java
new file mode 100644
index 000000000..6ec46dbd5
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/eventmodel/concepts/FieldTest.java
@@ -0,0 +1,134 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.eventmodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test fields.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class FieldTest {
+
+    @Test
+    public void testField() {
+        assertNotNull(new AxField());
+        assertNotNull(new AxField(new AxReferenceKey()));
+        assertNotNull(new AxField(new AxReferenceKey(), new AxArtifactKey()));
+        assertNotNull(new AxField(new AxReferenceKey(), new AxArtifactKey(), false));
+        assertNotNull(new AxField("LocalName", new AxArtifactKey(), false));
+        assertNotNull(new AxField("LocalName", new AxArtifactKey()));
+        assertNotNull(new AxField("LocalName", new AxArtifactKey(), false));
+
+        assertNotNull(new AxInputField());
+        assertNotNull(new AxInputField(new AxReferenceKey()));
+        assertNotNull(new AxInputField(new AxReferenceKey(), new AxArtifactKey()));
+        assertNotNull(new AxInputField(new AxReferenceKey(), new AxArtifactKey(), true));
+        assertNotNull(new AxInputField("LocalName", new AxArtifactKey()));
+        assertNotNull(new AxInputField(new AxInputField()));
+
+        assertNotNull(new AxOutputField());
+        assertNotNull(new AxOutputField(new AxReferenceKey()));
+        assertNotNull(new AxOutputField(new AxReferenceKey(), new AxArtifactKey()));
+        assertNotNull(new AxOutputField(new AxReferenceKey(), new AxArtifactKey(), false));
+        assertNotNull(new AxOutputField("LocalName", new AxArtifactKey()));
+        assertNotNull(new AxOutputField(new AxOutputField()));
+
+        final AxField field = new AxField();
+
+        final AxReferenceKey fieldKey = new AxReferenceKey("FieldName", "0.0.1", "PLN", "LN");
+        field.setKey(fieldKey);
+        assertEquals("FieldName:0.0.1:PLN:LN", field.getKey().getId());
+        assertEquals("FieldName:0.0.1:PLN:LN", field.getKeys().get(0).getId());
+
+        final AxArtifactKey schemaKey = new AxArtifactKey("SchemaName", "0.0.1");
+        field.setSchema(schemaKey);
+        assertEquals("SchemaName:0.0.1", field.getSchema().getId());
+
+        assertEquals(false, field.getOptional());
+        field.setOptional(true);
+        assertEquals(true, field.getOptional());
+
+        AxValidationResult result = new AxValidationResult();
+        result = field.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        field.setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = field.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        field.setKey(fieldKey);
+        result = new AxValidationResult();
+        result = field.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        field.setSchema(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = field.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        field.setSchema(schemaKey);
+        result = new AxValidationResult();
+        result = field.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        field.clean();
+
+        final AxField clonedField = new AxField(field);
+        assertEquals("AxField:(key=AxReferenceKey:(parentKeyName=FieldName,parentKeyVersion=0.0.1,"
+                        + "parentLocalName=PLN,localName=LN),fieldSchemaKey="
+                        + "AxArtifactKey:(name=SchemaName,version=0.0.1),optional=true)", clonedField.toString());
+
+        assertNotEquals(0, field.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(field, field); // NOSONAR
+        assertEquals(field, clonedField);
+        assertNotNull(field);
+        assertNotEquals(field, (Object) "Hello");
+        assertNotEquals(field, new AxField(AxReferenceKey.getNullKey(), AxArtifactKey.getNullKey(), false));
+        assertNotEquals(field, new AxField(fieldKey, AxArtifactKey.getNullKey(), false));
+        assertNotEquals(field, new AxField(fieldKey, schemaKey, false));
+        assertEquals(field, new AxField(fieldKey, schemaKey, true));
+
+        assertEquals(0, field.compareTo(field));
+        assertEquals(0, field.compareTo(clonedField));
+        assertNotEquals(0, field.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, field.compareTo(null));
+        assertNotEquals(0,
+                        field.compareTo(new AxField(AxReferenceKey.getNullKey(), AxArtifactKey.getNullKey(), false)));
+        assertNotEquals(0, field.compareTo(new AxField(fieldKey, AxArtifactKey.getNullKey(), false)));
+        assertNotEquals(0, field.compareTo(new AxField(fieldKey, schemaKey, false)));
+        assertEquals(0, field.compareTo(new AxField(fieldKey, schemaKey, true)));
+
+        assertNotNull(field.getKeys());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/eventmodel/handling/ApexEventModelTest.java b/model/src/test/java/org/onap/policy/apex/model/eventmodel/handling/ApexEventModelTest.java
new file mode 100644
index 000000000..21b97c454
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/eventmodel/handling/ApexEventModelTest.java
@@ -0,0 +1,279 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.eventmodel.handling;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEventModel;
+
+public class ApexEventModelTest {
+    private static final String VALID_MODEL_STRING = "***validation of model successful***";
+
+    private static final String OBSERVATION_MODEL_STRING = "\n"
+                    + "***observations noted during validation of model***\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event2,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event2,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "********************************";
+
+    private static final String WARNING_MODEL_STRING = "\n" + "***warnings issued during validation of model***\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:WARNING:nameSpace on event is blank\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:WARNING:nameSpace on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event2,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:WARNING:nameSpace on event is blank\n"
+                    + "AxArtifactKey:(name=event2,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event2,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "********************************";
+
+    private static final String INVALID_MODEL_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1):"
+                    + "org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation:INVALID:"
+                    + "keyInfoMap may not be empty\n" + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=smallEventModel,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=Schemas,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=BigIntType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=BooleanType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=IntType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=MapType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=SetType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=StringType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=smallEventMap,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=event0,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par0)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par2)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par3)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par4)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par5)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=par6)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=event1,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=theOnlyPar)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "duplicate key AxArtifactKey:(name=event1,version=0.0.1) found\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=event1,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "duplicate key AxReferenceKey:(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,"
+                    + "localName=theOnlyPar) found\n" + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event0,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=theOnlyPar)\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:INVALID:"
+                    + "parent key on parameter field AxReferenceKey:(parentKeyName=event0,parentKeyVersion=0.0.1,"
+                    + "parentLocalName=NULL,localName=theOnlyPar) does not equal event key\n"
+                    + "AxArtifactKey:(name=smallEventMap,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvents:INVALID:"
+                    + "key on event entry key AxArtifactKey:(name=event2,version=0.0.1) does not equal event value key "
+                    + "AxArtifactKey:(name=event1,version=0.0.1)\n" + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:INVALID:"
+                    + "parent key on parameter field AxReferenceKey:(parentKeyName=event0,parentKeyVersion=0.0.1,"
+                    + "parentLocalName=NULL,localName=theOnlyPar) does not equal event key\n"
+                    + "********************************";
+
+    private static final String INVALID_MODEL_MALSTRUCTURED_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1):"
+                    + "org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation:INVALID:"
+                    + "keyInfoMap may not be empty\n" + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=smallEventModel,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=KeyInfoMapKey,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=Schemas,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=SetType,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=smallEventMap,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=event1,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event1,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=theOnlyPar)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "duplicate key AxArtifactKey:(name=event1,version=0.0.1) found\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=event1,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "duplicate key AxReferenceKey:(parentKeyName=event1,parentKeyVersion=0.0.1,"
+                    + "parentLocalName=NULL,localName=theOnlyPar) found\n"
+                    + "AxArtifactKey:(name=smallEventModel,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEventModel:INVALID:"
+                    + "key information not found for parent key of key AxReferenceKey:"
+                    + "(parentKeyName=event1,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=theOnlyPar)\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "AxArtifactKey:(name=smallEventMap,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvents:INVALID:"
+                    + "key on event entry key AxArtifactKey:(name=event2,version=0.0.1) does not equal event value key "
+                    + "AxArtifactKey:(name=event1,version=0.0.1)\n" + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:source on event is blank\n"
+                    + "AxArtifactKey:(name=event1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvent:OBSERVATION:target on event is blank\n"
+                    + "********************************";
+
+    TestApexModel<AxEventModel> testApexModel;
+
+    /**
+     * Set up the test.
+     *
+     * @throws Exception exceptions from the test
+     */
+    @Before
+    public void setup() throws Exception {
+        testApexModel = new TestApexModel<AxEventModel>(AxEventModel.class, new DummyTestApexEventModelCreator());
+    }
+
+    @Test
+    public void testModelValid() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelValid();
+        assertEquals(VALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateObservation() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateObservation();
+        assertEquals(OBSERVATION_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateWarning() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateWarning();
+        assertEquals(WARNING_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateInvalidModel() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateInvalidModel();
+        assertEquals(INVALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateMalstructured() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateMalstructured();
+        assertEquals(INVALID_MODEL_MALSTRUCTURED_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelWriteReadJson() throws Exception {
+        testApexModel.testApexModelWriteReadJson();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/eventmodel/handling/DummyTestApexEventModelCreator.java b/model/src/test/java/org/onap/policy/apex/model/eventmodel/handling/DummyTestApexEventModelCreator.java
new file mode 100644
index 000000000..11685a6b4
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/eventmodel/handling/DummyTestApexEventModelCreator.java
@@ -0,0 +1,309 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.eventmodel.handling;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEventModel;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvents;
+import org.onap.policy.apex.model.eventmodel.concepts.AxField;
+
+public class DummyTestApexEventModelCreator implements TestApexModelCreator<AxEventModel> {
+
+    @Override
+    public AxEventModel getModel() {
+        final AxContextSchema axSchema0 =
+                new AxContextSchema(new AxArtifactKey("BooleanType", "0.0.1"), "Java", "java.lang.Boolean");
+        final AxContextSchema axSchema1 =
+                new AxContextSchema(new AxArtifactKey("IntType", "0.0.1"), "Java", "java.lang.Integer");
+        final AxContextSchema axSchema2 =
+                new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java", "java.lang.String");
+        final AxContextSchema axSchema3 = new AxContextSchema(new AxArtifactKey("KeyType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey");
+        final AxContextSchema axSchema4 = new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation");
+        final AxContextSchema axSchema5 =
+                new AxContextSchema(new AxArtifactKey("BigIntType", "0.0.1"), "Java", "java.math.BigInteger");
+        final AxContextSchema axSchema6 = new AxContextSchema(new AxArtifactKey("ModelType", "0.0.1"), "Java",
+                "org.onap.policy.apex.model.basicmodel.concepts.AxModel");
+
+        final AxContextSchemas dataTypes = new AxContextSchemas(new AxArtifactKey("Schemas", "0.0.1"));
+        dataTypes.getSchemasMap().put(axSchema0.getKey(), axSchema0);
+        dataTypes.getSchemasMap().put(axSchema1.getKey(), axSchema1);
+        dataTypes.getSchemasMap().put(axSchema2.getKey(), axSchema2);
+        dataTypes.getSchemasMap().put(axSchema3.getKey(), axSchema3);
+        dataTypes.getSchemasMap().put(axSchema4.getKey(), axSchema4);
+        dataTypes.getSchemasMap().put(axSchema5.getKey(), axSchema5);
+        dataTypes.getSchemasMap().put(axSchema6.getKey(), axSchema6);
+
+        final AxEvents eventMap = new AxEvents(new AxArtifactKey("smallEventMap", "0.0.1"));
+
+        final AxEvent event0 = new AxEvent(new AxArtifactKey("event0", "0.0.1"),
+                "org.onap.policy.apex.model.eventmodel.events", "Source", "Target");
+        event0.getParameterMap().put("par0",
+                new AxField(new AxReferenceKey(event0.getKey(), "par0"), axSchema0.getKey()));
+        event0.getParameterMap().put("par1",
+                new AxField(new AxReferenceKey(event0.getKey(), "par1"), axSchema1.getKey()));
+        event0.getParameterMap().put("par2",
+                new AxField(new AxReferenceKey(event0.getKey(), "par2"), axSchema2.getKey()));
+        event0.getParameterMap().put("par3",
+                new AxField(new AxReferenceKey(event0.getKey(), "par3"), axSchema6.getKey()));
+        event0.getParameterMap().put("par4",
+                new AxField(new AxReferenceKey(event0.getKey(), "par4"), axSchema4.getKey()));
+        event0.getParameterMap().put("par5",
+                new AxField(new AxReferenceKey(event0.getKey(), "par5"), axSchema5.getKey()));
+        event0.getParameterMap().put("par6",
+                new AxField(new AxReferenceKey(event0.getKey(), "par6"), axSchema5.getKey()));
+        eventMap.getEventMap().put(event0.getKey(), event0);
+
+        final AxEvent event1 = new AxEvent(new AxArtifactKey("event1", "0.0.1"),
+                "org.onap.policy.apex.model.eventmodel.events", "Source", "Target");
+        event1.getParameterMap().put("theOnlyPar",
+                new AxField(new AxReferenceKey(event1.getKey(), "theOnlyPar"), axSchema3.getKey()));
+        eventMap.getEventMap().put(event1.getKey(), event1);
+
+        final AxEvent event2 = new AxEvent(new AxArtifactKey("event2", "0.0.1"),
+                "org.onap.policy.apex.model.eventmodel.events", "Source", "Target");
+        eventMap.getEventMap().put(event2.getKey(), event2);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+
+        final AxEventModel eventModel =
+                new AxEventModel(new AxArtifactKey("EventModel", "0.0.1"), dataTypes, keyInformation, eventMap);
+        keyInformation.generateKeyInfo(eventModel);
+
+        eventModel.validate(new AxValidationResult());
+        return eventModel;
+    }
+
+    @Override
+    public AxEventModel getInvalidModel() {
+        final AxContextSchema axSchema0 =
+                new AxContextSchema(new AxArtifactKey("BooleanType", "0.0.1"), "Java", "java.lang.Zoolean");
+        final AxContextSchema axSchema1 =
+                new AxContextSchema(new AxArtifactKey("IntType", "0.0.1"), "Java", "java.lang.Integer");
+        final AxContextSchema axSchema2 =
+                new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java", "java.lang.String");
+        final AxContextSchema axSchema3 =
+                new AxContextSchema(new AxArtifactKey("SetType", "0.0.1"), "Java", "java.util.Set");
+        final AxContextSchema axSchema4 =
+                new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java", "java.util.Map");
+        final AxContextSchema axSchema5 =
+                new AxContextSchema(new AxArtifactKey("BigIntType", "0.0.1"), "Java", "java.math.BigInteger");
+
+        final AxContextSchemas dataTypes = new AxContextSchemas(new AxArtifactKey("Schemas", "0.0.1"));
+        dataTypes.getSchemasMap().put(axSchema0.getKey(), axSchema0);
+        dataTypes.getSchemasMap().put(axSchema1.getKey(), axSchema1);
+        dataTypes.getSchemasMap().put(axSchema2.getKey(), axSchema2);
+        dataTypes.getSchemasMap().put(axSchema3.getKey(), axSchema3);
+        dataTypes.getSchemasMap().put(axSchema4.getKey(), axSchema4);
+        dataTypes.getSchemasMap().put(axSchema5.getKey(), axSchema5);
+
+        final AxEvents eventMap = new AxEvents(new AxArtifactKey("smallEventMap", "0.0.1"));
+
+        final AxEvent event0 =
+                new AxEvent(new AxArtifactKey("event0", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        event0.getParameterMap().put("par0",
+                new AxField(new AxReferenceKey(event0.getKey(), "par0"), axSchema0.getKey()));
+        event0.getParameterMap().put("par1",
+                new AxField(new AxReferenceKey(event0.getKey(), "par1"), axSchema1.getKey()));
+        event0.getParameterMap().put("par2",
+                new AxField(new AxReferenceKey(event0.getKey(), "par2"), axSchema2.getKey()));
+        event0.getParameterMap().put("par3",
+                new AxField(new AxReferenceKey(event0.getKey(), "par3"), axSchema3.getKey()));
+        event0.getParameterMap().put("par4",
+                new AxField(new AxReferenceKey(event0.getKey(), "par4"), axSchema4.getKey()));
+        event0.getParameterMap().put("par5",
+                new AxField(new AxReferenceKey(event0.getKey(), "par5"), axSchema5.getKey()));
+        event0.getParameterMap().put("par6",
+                new AxField(new AxReferenceKey(event0.getKey(), "par6"), axSchema5.getKey()));
+        eventMap.getEventMap().put(event0.getKey(), event0);
+
+        final AxEvent event1 =
+                new AxEvent(new AxArtifactKey("event1", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        event1.getParameterMap().put("theOnlyPar",
+                new AxField(new AxReferenceKey(event0.getKey(), "theOnlyPar"), axSchema3.getKey()));
+        eventMap.getEventMap().put(event1.getKey(), event1);
+
+        final AxEvent event2 =
+                new AxEvent(new AxArtifactKey("event2", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        eventMap.getEventMap().put(event2.getKey(), event1);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+
+        final AxEventModel eventModel =
+                new AxEventModel(new AxArtifactKey("smallEventModel", "0.0.1"), dataTypes, keyInformation, eventMap);
+
+        return eventModel;
+    }
+
+    @Override
+    public AxEventModel getMalstructuredModel() {
+        final AxContextSchema axSchema3 =
+                new AxContextSchema(new AxArtifactKey("SetType", "0.0.1"), "Java", "java.util.Set");
+        final AxContextSchemas dataTypes = new AxContextSchemas(new AxArtifactKey("Schemas", "0.0.1"));
+        dataTypes.getSchemasMap().put(axSchema3.getKey(), axSchema3);
+
+        final AxEvents eventMap = new AxEvents(new AxArtifactKey("smallEventMap", "0.0.1"));
+
+        final AxEvent event1 =
+                new AxEvent(new AxArtifactKey("event1", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        event1.getParameterMap().put("theOnlyPar",
+                new AxField(new AxReferenceKey(event1.getKey(), "theOnlyPar"), axSchema3.getKey()));
+        eventMap.getEventMap().put(event1.getKey(), event1);
+
+        final AxEvent event2 =
+                new AxEvent(new AxArtifactKey("event2", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        eventMap.getEventMap().put(event2.getKey(), event1);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+
+        final AxEventModel eventModel =
+                new AxEventModel(new AxArtifactKey("smallEventModel", "0.0.1"), dataTypes, keyInformation, eventMap);
+
+        eventModel.validate(new AxValidationResult());
+
+        return eventModel;
+    }
+
+    @Override
+    public AxEventModel getWarningModel() {
+        final AxContextSchema axSchema0 =
+                new AxContextSchema(new AxArtifactKey("BooleanType", "0.0.1"), "Java", "java.lang.Boolean");
+        final AxContextSchema axSchema1 =
+                new AxContextSchema(new AxArtifactKey("IntType", "0.0.1"), "Java", "java.lang.Integer");
+        final AxContextSchema axSchema2 =
+                new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java", "java.lang.String");
+        final AxContextSchema axSchema3 =
+                new AxContextSchema(new AxArtifactKey("SetType", "0.0.1"), "Java", "java.util.Set");
+        final AxContextSchema axSchema4 =
+                new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java", "java.util.Map");
+        final AxContextSchema axSchema5 =
+                new AxContextSchema(new AxArtifactKey("BigIntType", "0.0.1"), "Java", "java.math.BigInteger");
+        final AxContextSchemas dataTypes = new AxContextSchemas(new AxArtifactKey("Schemas", "0.0.1"));
+        dataTypes.getSchemasMap().put(axSchema0.getKey(), axSchema0);
+        dataTypes.getSchemasMap().put(axSchema1.getKey(), axSchema1);
+        dataTypes.getSchemasMap().put(axSchema2.getKey(), axSchema2);
+        dataTypes.getSchemasMap().put(axSchema3.getKey(), axSchema3);
+        dataTypes.getSchemasMap().put(axSchema4.getKey(), axSchema4);
+        dataTypes.getSchemasMap().put(axSchema5.getKey(), axSchema5);
+
+        final AxEvents eventMap = new AxEvents(new AxArtifactKey("smallEventMap", "0.0.1"));
+
+        final AxEvent event0 = new AxEvent(new AxArtifactKey("event0", "0.0.1"), "");
+        event0.getParameterMap().put("par0",
+                new AxField(new AxReferenceKey(event0.getKey(), "par0"), axSchema0.getKey()));
+        event0.getParameterMap().put("par1",
+                new AxField(new AxReferenceKey(event0.getKey(), "par1"), axSchema1.getKey()));
+        event0.getParameterMap().put("par2",
+                new AxField(new AxReferenceKey(event0.getKey(), "par2"), axSchema2.getKey()));
+        event0.getParameterMap().put("par3",
+                new AxField(new AxReferenceKey(event0.getKey(), "par3"), axSchema3.getKey()));
+        event0.getParameterMap().put("par4",
+                new AxField(new AxReferenceKey(event0.getKey(), "par4"), axSchema4.getKey()));
+        event0.getParameterMap().put("par5",
+                new AxField(new AxReferenceKey(event0.getKey(), "par5"), axSchema5.getKey()));
+        eventMap.getEventMap().put(event0.getKey(), event0);
+
+        final AxEvent event1 = new AxEvent(new AxArtifactKey("event1", "0.0.1"), "");
+        event1.getParameterMap().put("theOnlyPar",
+                new AxField(new AxReferenceKey(event1.getKey(), "theOnlyPar"), axSchema3.getKey()));
+        eventMap.getEventMap().put(event1.getKey(), event1);
+
+        final AxEvent event2 = new AxEvent(new AxArtifactKey("event2", "0.0.1"), "");
+        eventMap.getEventMap().put(event2.getKey(), event2);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+
+        final AxEventModel eventModel =
+                new AxEventModel(new AxArtifactKey("smallEventModel", "0.0.1"), dataTypes, keyInformation, eventMap);
+        eventModel.getKeyInformation().generateKeyInfo(eventModel);
+        eventModel.validate(new AxValidationResult());
+
+        return eventModel;
+    }
+
+    @Override
+    public AxEventModel getObservationModel() {
+        final AxContextSchema axSchema0 =
+                new AxContextSchema(new AxArtifactKey("BooleanType", "0.0.1"), "Java", "java.lang.Boolean");
+        final AxContextSchema axSchema1 =
+                new AxContextSchema(new AxArtifactKey("IntType", "0.0.1"), "Java", "java.lang.Integer");
+        final AxContextSchema axSchema2 =
+                new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java", "java.lang.String");
+        final AxContextSchema axSchema3 =
+                new AxContextSchema(new AxArtifactKey("SetType", "0.0.1"), "Java", "java.util.Set");
+        final AxContextSchema axSchema4 =
+                new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java", "java.util.Map");
+        final AxContextSchema axSchema5 =
+                new AxContextSchema(new AxArtifactKey("BigIntType", "0.0.1"), "Java", "java.math.BigInteger");
+        final AxContextSchemas schemas = new AxContextSchemas(new AxArtifactKey("Schemas", "0.0.1"));
+        schemas.getSchemasMap().put(axSchema0.getKey(), axSchema0);
+        schemas.getSchemasMap().put(axSchema1.getKey(), axSchema1);
+        schemas.getSchemasMap().put(axSchema2.getKey(), axSchema2);
+        schemas.getSchemasMap().put(axSchema3.getKey(), axSchema3);
+        schemas.getSchemasMap().put(axSchema4.getKey(), axSchema4);
+        schemas.getSchemasMap().put(axSchema5.getKey(), axSchema5);
+
+        final AxEvents eventMap = new AxEvents(new AxArtifactKey("smallEventMap", "0.0.1"));
+
+        final AxEvent event0 =
+                new AxEvent(new AxArtifactKey("event0", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        event0.getParameterMap().put("par0",
+                new AxField(new AxReferenceKey(event0.getKey(), "par0"), axSchema0.getKey()));
+        event0.getParameterMap().put("par1",
+                new AxField(new AxReferenceKey(event0.getKey(), "par1"), axSchema1.getKey()));
+        event0.getParameterMap().put("par2",
+                new AxField(new AxReferenceKey(event0.getKey(), "par2"), axSchema2.getKey()));
+        event0.getParameterMap().put("par3",
+                new AxField(new AxReferenceKey(event0.getKey(), "par3"), axSchema3.getKey()));
+        event0.getParameterMap().put("par4",
+                new AxField(new AxReferenceKey(event0.getKey(), "par4"), axSchema4.getKey()));
+        event0.getParameterMap().put("par5",
+                new AxField(new AxReferenceKey(event0.getKey(), "par5"), axSchema5.getKey()));
+        eventMap.getEventMap().put(event0.getKey(), event0);
+
+        final AxEvent event1 =
+                new AxEvent(new AxArtifactKey("event1", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        event1.getParameterMap().put("theOnlyPar",
+                new AxField(new AxReferenceKey(event1.getKey(), "theOnlyPar"), axSchema3.getKey()));
+        eventMap.getEventMap().put(event1.getKey(), event1);
+
+        final AxEvent event2 =
+                new AxEvent(new AxArtifactKey("event2", "0.0.1"), "org.onap.policy.apex.model.eventmodel.events");
+        eventMap.getEventMap().put(event2.getKey(), event2);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+
+        final AxEventModel eventModel =
+                new AxEventModel(new AxArtifactKey("smallEventModel", "0.0.1"), schemas, keyInformation, eventMap);
+        eventModel.getKeyInformation().generateKeyInfo(eventModel);
+        eventModel.validate(new AxValidationResult());
+
+        return eventModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexApiResultTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexApiResultTest.java
new file mode 100644
index 000000000..3c2af18ea
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexApiResultTest.java
@@ -0,0 +1,80 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.Arrays;
+import org.junit.Test;
+import org.onap.policy.apex.model.modelapi.ApexApiResult.Result;
+
+/**
+ * Test API results.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexApiResultTest {
+
+    @Test
+    public void testApiResult() {
+        assertNotNull(new ApexApiResult());
+
+        for (final Result result : Result.values()) {
+            assertNotNull(new ApexApiResult(result));
+        }
+
+        assertNotNull(new ApexApiResult(Result.SUCCESS, "Result Message"));
+        assertNotNull(new ApexApiResult(Result.FAILED, new IOException("IO Exception message")));
+        assertNotNull(new ApexApiResult(Result.FAILED, "Result Message", new IOException("IO Exception message")));
+
+        final ApexApiResult result =
+                new ApexApiResult(Result.FAILED, "Result Message", new IOException("IO Exception message"));
+
+        assertFalse(result.isOk());
+        assertTrue(result.isNok());
+        assertEquals(Result.FAILED, result.getResult());
+        assertEquals("Result Message\nIO Exception message\njava.io.IOExce", result.getMessage().substring(0, 50));
+
+        final ApexApiResult result2 = new ApexApiResult(Result.SUCCESS);
+        result2.addMessage(null);
+        assertEquals("", result2.getMessage());
+        result2.addMessage("");
+        assertEquals("", result2.getMessage());
+        result2.addMessage("funky message");
+        assertEquals("funky message\n", result2.getMessage());
+
+        result2.setResult(Result.OTHER_ERROR);
+        assertEquals(Result.OTHER_ERROR, result2.getResult());
+
+        final String[] messages = {"First Message", "Second Message", "Third Message"};
+        result2.setMessages(Arrays.asList(messages));
+        assertEquals("First Message", result2.getMessages().get(0));
+        assertEquals("Second Message", result2.getMessages().get(1));
+        assertEquals("Third Message", result2.getMessages().get(2));
+
+        assertEquals("result: OTHER_ERROR\nFirst Message\nSecond Message\nThird Message\n", result2.toString());
+        assertEquals("{\n" + "\"result\": \"OTHER_ERROR\",\n" + "\"messages\": [\n" + "\"First Message\",\n"
+                + "\"Second Message\",\n" + "\"Third Message\"]\n" + "}\n", result2.toJson());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiContextAlbumTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiContextAlbumTest.java
new file mode 100644
index 000000000..5ce6b6760
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiContextAlbumTest.java
@@ -0,0 +1,176 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/**
+ * Context album for API tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexEditorApiContextAlbumTest {
+    @Test
+    public void testContextAlbumCrud() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.validateContextAlbum(null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.validateContextAlbum("%%%$£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createContextAlbum("MyMap002", "0.0.2", "APPLICATION", "true", "MapType", "0.0.1",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", "0.1.2", "ZOOBY", "false", "MapType", "0.0.1",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 012");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", "0.1.4", "UNDEFINED", null, "MapType", "0.0.1",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 014");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "+++", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "MapZooby", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "MapType", "--++", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "MapType", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "MapType", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", null, "EPHEMERAL", "false", "MapType", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap002", "0.0.2", "APPLICATION", "true", "MapType", null,
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap011", "0.1.2", "APPLICATION", "true", "MapType", "0.0.1",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deleteContextAlbum("MyMap012", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextAlbum("MyMap012", "0.1.2", "ZOOBY", "false", "MapType", "0.0.1",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 012");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.validateContextAlbum(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateContextAlbum(null, null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap002", "0.0.2", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap002", "0.0.2", "ZOOBY", "true", null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap002", "0.0.2", null, null, null, null,
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, null, "true", null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap015", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap014", "0.1.5", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", "false", null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", "false", "StringType", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", "false", "String", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", "false", "StringType", "0.0.2", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", "false", "StringType", "0.0.1", null,
+            null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextAlbum("MyMap012", null, "APPLICATION", "Hello", "StringType", "0.0.1", null,
+            null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listContextAlbum("@£%%$", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.listContextAlbum(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listContextAlbum("MyMap012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listContextAlbum("MyMap012", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listContextAlbum("MyMap012", "0.2.5");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listContextAlbum("MyMap014", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteContextAlbum("@£%%$", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteContextAlbum("MyMap012", "0.1.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteContextAlbum("MyMap012oooo", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listContextAlbum("MyMap012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(3, result.getMessages().size());
+
+        result = apexModel.deleteContextAlbum("MyMap012", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listContextAlbum("MyMap012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.deleteContextAlbum("MyMap012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.listContextAlbum("MyMap012", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteContextAlbum(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+
+        result = apexModel.listContextAlbum(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(0, result.getMessages().size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiContextSchemaTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiContextSchemaTest.java
new file mode 100644
index 000000000..20310a29e
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiContextSchemaTest.java
@@ -0,0 +1,153 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/**
+ * Context schema for API tests.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexEditorApiContextSchemaTest {
+    @Test
+    public void testContextSchemaCrud() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.validateContextSchemas(null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.validateContextSchemas("%%%$£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listContextSchemas(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createContextSchema("Hello", "0.0.2", "Java", "java.lang.String",
+                "1fa2e430-f2b2-11e6-bc64-92361f002671", "A description of hello");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextSchema("Hello", "0.1.2", "Java", "java.lang.String",
+                "1fa2e430-f2b2-11e6-bc64-92361f002672", "A description of hola");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextSchema("Hello", "0.1.4", "Java", "java.lang.String",
+                "1fa2e430-f2b2-11e6-bc64-92361f002672", "A description of connichi wa");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextSchema("Hello", null, "Java", "java.lang.String", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextSchema("Hello", null, "Java", "java.lang.String", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.deleteContextSchema("Hello", "0.1.4");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextSchema("Hello", "0.1.4", "Java", "java.lang.String",
+                "1fa2e430-f2b2-11e6-bc64-92361f002672", "A description of connichi wa");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createContextSchema("Hello2", null, null, "java.lang.String", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextSchema("Hello2", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createContextSchema("Hello2", null, "Java", "java.lang.String", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createContextSchema("Hello", "0.1.2", "Java", "java.lang.Float",
+                "1fa2e430-f2b2-11e6-bc64-92361f002672", "A description of hola");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.deleteContextSchema("Hello", "0.1.4");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createContextSchema("Hello", "0.1.4", "Java", "java.lang.String",
+                "1fa2e430-f2b2-11e6-bc64-92361f002672", "A description of connichi wa");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.validateContextSchemas(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateContextSchema(null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.updateContextSchema("Hello", "0.0.2", null, null, null, "An updated description of hello");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextSchema("Hello", "0.0.2", null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateContextSchema("Hello", "0.1.2", "Java", "java.lang.Integer",
+                "1fa2e430-f2b2-11e6-bc64-92361f002673", "A further updated description of hola");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateContextSchema("Hello2", "0.0.2", null, null, null, "An updated description of hello");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listContextSchemas("@£%%$", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.listContextSchemas("Hello", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.listContextSchemas("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+
+        result = apexModel.listContextSchemas(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(9, result.getMessages().size());
+
+        result = apexModel.deleteContextSchema("@£%%$", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteContextSchema("Hello", "0.1.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteContextSchema("Hellooooo", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listContextSchemas("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+
+        result = apexModel.deleteContextSchema("Hello", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listContextSchemas("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(3, result.getMessages().size());
+
+        result = apexModel.deleteContextSchema("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listContextSchemas("Hello", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listContextSchemas(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deleteContextSchema(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(5, result.getMessages().size());
+
+        result = apexModel.listContextSchemas(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(0, result.getMessages().size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiEventTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiEventTest.java
new file mode 100644
index 000000000..ac9265e84
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiEventTest.java
@@ -0,0 +1,202 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ *  Modifications Copyright (C) 2022 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/**
+ * Test events for API tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexEditorApiEventTest {
+    @Test
+    public void testEventCrud() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.validateEvent(null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.validateEvent("%%%$£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createEvent("MyEvent002", "0.0.2", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEvent("MyEvent012", "0.1.2", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEvent("MyEvent012", "0.1.4", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 014", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEvent("MyEvent012", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEvent("MyEvent012", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createEvent("MyEvent002", "0.0.2", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createEvent("@£$%^", "0.2.5", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteEvent("MyEvent012", "0.1.4");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEvent("MyEvent012", "0.1.4", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 014", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.validateEvent(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateEvent(null, null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result =
+            apexModel.updateEvent("MyEvent012", "0.1.2", "Another Namespace", null, "Another target", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateEvent("MyEvent002", "0.0.2", "My Namespace", "My Source", "my target",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateEvent("MyEvent012", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateEvent("MyEvent015", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateEvent("MyEvent014", "0.1.5", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateEvent("@£$%^^", "0.6.9", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.listEvent("@£$%", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listEvent(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEvent("MyEvent012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEvent("MyEvent012", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEvent("MyEvent012", "0.2.5");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listEvent("MyEvent123", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteEvent("@£$%^", "0.1.1");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deleteEvent("MyEvent012", "0.1.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteEvent("MyEvent012oooo", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listEvent("MyEvent012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(3, result.getMessages().size());
+
+        result = apexModel.deleteEvent("MyEvent012", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listEvent("MyEvent012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.deleteEvent("MyEvent012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listEvent("MyEvent012", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createEventPar("MyEvent123", null, "NewPar00", null, null, false);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createEventPar("MyEvent002", "4.5.6", "NewPar00", null, null, true);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createEventPar("MyEvent002", "0.1.4", "NewPar00", null, null, false);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createEventPar("MyEvent002", "0.0.2", "NewPar00", null, null, true);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.createContextSchema("eventContextItem0", "0.0.1", "Java", "java.lang.Integer",
+            "1fa2e430-f2b2-11e6-bc64-92361f002673", "A further updated description of hola");
+        result = apexModel.createEventPar("MyEvent002", "0.0.2", "NewPar00", "eventContextItem0", null, false);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEventPar("MyEvent002", "0.0.2", "NewPar00", "eventContextItem0", null, true);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createEventPar("MyEvent002", "0.0.2", "NewPar01", "eventContextItem0", "0.0.1", false);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEventPar("MyEvent002", "0.0.2", "NewPar02", "eventContextItem0", "0.0.2", true);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createEventPar("MyEvent002", null, "NewPar02", "eventContextItem0", null, false);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createEventPar("MyEvent002", null, "NewPar03", "eventContextItem0", null, true);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listEventPar("@£%%$", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", "0.0.1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", "0.0.2", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", "0.0.2", "NewPar01");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", "0.0.2", "NewPar02");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteEventPar("@££%%%", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deleteEventPar("NonExistantEvent", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(4, apexModel.listEventPar("MyEvent002", null, null).getMessages().size());
+        result = apexModel.deleteEventPar("MyEvent002", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(4, apexModel.listEventPar("MyEvent002", null, null).getMessages().size());
+        result = apexModel.deleteEventPar("MyEvent002", null, "NewPar02");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(3, apexModel.listEventPar("MyEvent002", null, null).getMessages().size());
+        result = apexModel.deleteEventPar("MyEvent002", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deleteEventPar("MyEvent002", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listEventPar("MyEvent002", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteEvent(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+
+        result = apexModel.listEvent(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(0, result.getMessages().size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiKeyInfoTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiKeyInfoTest.java
new file mode 100644
index 000000000..2519b8cb2
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiKeyInfoTest.java
@@ -0,0 +1,137 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/**
+ * Key information for API tests.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexEditorApiKeyInfoTest {
+
+    @Test
+    public void testKeyInfoCrud() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.validateKeyInformation(null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.validateKeyInformation("%%%$£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createKeyInformation(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.createKeyInformation("Hello", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002671",
+                "A description of hello");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createKeyInformation("Hello", "0.1.2", "1fa2e430-f2b2-11e6-bc64-92361f002672",
+                "A description of hola");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createKeyInformation("Hello", "0.1.4", "1fa2e430-f2b2-11e6-bc64-92361f002672",
+                "A description of connichi wa");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createKeyInformation("Hello", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createKeyInformation("Hello", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.createKeyInformation("Hello", "0.1.2", "1fa2e430-f2b2-11e6-bc64-92361f002672",
+                "A description of hola");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.validateKeyInformation(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateKeyInformation(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.updateKeyInformation("Hello", "0.0.2", null, "An updated description of hello");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateKeyInformation("Hello", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateKeyInformation("Hello", "0.1.2", "1fa2e430-f2b2-11e6-bc64-92361f002673",
+                "A further updated description of hola");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateKeyInformation("Hello2", "0.0.2", null, "An updated description of hello");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listKeyInformation(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listKeyInformation("%%%$$", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.listKeyInformation("Hello", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.listKeyInformation("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+
+        result = apexModel.deleteKeyInformation("Hello", "0.1.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteKeyInformation("Hellooooo", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listKeyInformation("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+
+        result = apexModel.listKeyInformation(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(22, result.getMessages().size());
+
+        result = apexModel.deleteKeyInformation("%%%$$", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteKeyInformation("Hello", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listKeyInformation("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(3, result.getMessages().size());
+
+        result = apexModel.deleteKeyInformation("Hello", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listKeyInformation("Hello", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteKeyInformation(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(18, result.getMessages().size());
+
+        result = apexModel.listKeyInformation(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(0, result.getMessages().size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiPolicyTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiPolicyTest.java
new file mode 100644
index 000000000..0a4d72214
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiPolicyTest.java
@@ -0,0 +1,1023 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+/**
+ * Test policies for API.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexEditorApiPolicyTest {
+    @Test
+    public void testMyTestPolicyCrud() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.validatePolicy(null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.validatePolicy("%%%$£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createPolicy("MyPolicy002", "0.0.2", "SomeTemplate", "AState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicy("MyPolicy002", "0.0.2", "SomeTemplate", "AState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicy("MyPolicy012", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicy("MyPolicy012", null, "SomeTemplate", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicy("MyPolicy013", null, null, "AState", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicy("MyPolicy012", null, "SomeTemplate", "AState", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicy("MyPolicy002", "0.0.2", "SomeTemplate", "AState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicy("MyPolicy012", "0.1.2", "SomeTemplate", "AState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicy("MyTestPolicy", "0.0.1", "SomeTemplate", "TestState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deletePolicy("MyPolicy002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicy("MyPolicy002", "0.0.2", "SomeTemplate", "AState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.validatePolicy(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updatePolicy("@£$$", "0.0.2", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy002", "0.0.2", null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy002", "0.0.1", null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy002", "0.0.2", "SomeOtherTemplate", "BState",
+            "1fa2e430-f2b2-11e6-bc64-92361f002700", "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy012", null, "SomeOtherTemplate", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy012", null, null, "CState", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy012", null, "SomeOtherTemplate", "BState", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy015", null, "SomeOtherTemplate", "DState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicy("MyPolicy014", "0.1.5", "SomeOtherTemplate", "EState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listPolicy("@£$%%", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicy(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(6, result.getMessages().size());
+        result = apexModel.listPolicy("MyPolicy012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicy("MyPolicy012", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicy("MyPolicy012", "0.2.5");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicy("MyPolicy014", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deletePolicy("@£$%", "0.1.1");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deletePolicy("MyPolicy012", "0.1.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deletePolicy("MyPolicy012oooo", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listPolicy("MyPolicy012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.deletePolicy("MyPolicy002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+
+        result = apexModel.listPolicy("MyPolicy012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.deletePolicy("MyPolicy012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.createPolicyState(null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyState("MyPolicy123", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyState("MyPolicy123", null, "AState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.2", "AState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "ATrigger", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", null, "ATask", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", null, "task", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", null, "task", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", null, "AState", "inEvent", null, "task", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "AState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "BState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "CState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "DState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updatePolicyState(null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyState("MyPolicy123", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyState("MyPolicy123", null, "AState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", "0.0.2", "AState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "ZState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "ATrigger", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", null, "ATask", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", null, "task", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", null, "task", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", null, "AState", "inEvent", null, "task", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", "0.0.1", "AState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", "0.0.1", "BState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", "0.0.1", "CState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyState("MyTestPolicy", "0.0.1", "DState", "inEvent", "0.0.1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listPolicyState("MyTestPolicy", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+        result = apexModel.listPolicyState(null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyState("SomeOtherPolicy", "0.0.1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyState("SomeOtherPolicy", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyState("MyTestPolicy", "0.0.2", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyState("MyTestPolicy", "0.0.1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+        result = apexModel.listPolicyState("MyTestPolicy", "0.0.1", "CState");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyState("MyTestPolicy", null, "CState");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyState("MyTestPolicy", "0.0.1", "AState");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyState("MyTestPolicy", "0.0.1", "EState");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deletePolicyState("@£$$", "0.0.2", "Trigger04");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        assertEquals(4, apexModel.listPolicyState("MyTestPolicy", null, null).getMessages().size());
+        result = apexModel.deletePolicyState("MyTestPolicy", "0.0.2", "Trigger04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(4, apexModel.listPolicyState("MyTestPolicy", null, null).getMessages().size());
+        result = apexModel.deletePolicyState("MyTestPolicy", null, "CState");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyState("MyTestPolicy", null, "ZState");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(3, apexModel.listPolicyState("MyTestPolicy", null, null).getMessages().size());
+        result = apexModel.deletePolicyState("MyTestPolicy", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listPolicyState("MyTestPolicy", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyState("MyTestPolicy", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "TestState1", "inEvent", "0.0.1", "task",
+            "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "TestState2", "outEvent0", "0.0.1", "task",
+            "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createPolicyState("MyTestPolicy", "0.0.1", "TestState3", "outEvent1", "0.0.1", "task",
+            "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createPolicyStateTaskSelectionLogic(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "1.2.3", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "NewTSL00", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "UNDEFINED",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "MVEL",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "JAVA",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "JYTHON",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", "JAVASCRIPT",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", "JRUBY",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updatePolicyStateTaskSelectionLogic(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState99", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy2", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy1", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "NonExistantState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "",
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1", "MVEL",
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyPolicy012", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", null,
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyPolicy015", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyPolicy014", "0.1.5", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listPolicyStateTaskSelectionLogic(null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("zooby", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("zooby", null, "looby");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("zooby", null, "TestState1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("MyTestPolicy", null, "looby");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.2", "TestState1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+
+        result = apexModel.deletePolicyStateTaskSelectionLogic(null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("zooby", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("zooby", null, "looby");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("zooby", null, "TestState1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", null, "looby");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.2", "TestState1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", null,
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.createPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1", "JRUBY",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listPolicyStateTaskSelectionLogic("MyTestPolicy", null, "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateTaskSelectionLogic("MyTestPolicy", "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createPolicyStateOutput(null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", null, "SomeState", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", null, "SomeState", "SomeOutput", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "1.2.3", "TestState1", "SomeOutput", null, null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOutput", null, null,
+            null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOutput",
+            "SomeDummyEvent", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOutput", "inEvent",
+            "1.2.3", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOutput", "inEvent",
+            "0.0.1", "SomeDummyNextState");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOutput", "inEvent",
+            "0.0.1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOtherOutput", "inEvent",
+            "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOtherOutput", "inEvent",
+            "0.0.1", "TestState2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOtherOutput", "inEvent",
+            "0.0.1", "TestState2");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState2", "AnotherOtherOutput",
+            "outEvent0", "0.0.1", "TestState3");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState2", "YetAnotherOtherOutput",
+            "outEvent0", "0.0.1", "TestState3");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listPolicyStateOutput(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.2", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, "SomeState", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState2", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "YetAnotherOtherOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState2", "YetAnotherOtherOutput");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState3", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deletePolicyStateOutput(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", "0.0.2", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", null, "SomeState", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", "0.0.1", "TestState3", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", "0.0.1", "TestState3", "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, "TestState1", null);
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", null, "TestState1", "SomeOutput");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, "TestState2", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.deletePolicyStateOutput("MyTestPolicy", null, "TestState2", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicyStateOutput("MyTestPolicy", null, "TestState2", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOutput", "inEvent",
+            "0.0.1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOtherOutput", "inEvent",
+            "0.0.1", "TestState1");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState1", "SomeOtherOutput", "inEvent",
+            "0.0.1", "TestState2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState2", "AnotherOtherOutput",
+            "outEvent0", "0.0.1", "TestState3");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateOutput("MyTestPolicy", "0.0.1", "TestState2", "YetAnotherOtherOutput",
+            "outEvent0", "0.0.1", "TestState3");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createPolicyStateFinalizerLogic(null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, "SomeState", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, "SomeState", "SFLName01", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "1.2.3", "TestState1", "SFLName01", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName01", null,
+            null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName01",
+            "NewTSL00", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName02",
+            "UNDEFINED", "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName03", "MVEL",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName03", "MVEL",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName04", "JAVA",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName05", "JYTHON",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName06",
+            "JAVASCRIPT", "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName07", "JRUBY",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updatePolicyStateFinalizerLogic(null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", null, "TestState99", "SomeSFLName", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy2", null, "TestState1", "SomeSFLName", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy1", "0.0.2", "TestState1", "SomeSFLName", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "NonEistantSFL", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName06", null,
+            null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName06", "",
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName06", "MVEL",
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyPolicy012", null, "TestState1", "SFLName06", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName06", null,
+            "Some Other Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName06", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyPolicy015", null, "TestState1", "SFLName06", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updatePolicyStateFinalizerLogic("MyPolicy014", "0.1.5", "TestState1", "SFLName06", null,
+            null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listPolicyStateFinalizerLogic(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", "0.0.2", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "SomeState", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("zooby", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("zooby", null, "looby", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("zooby", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "looby", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", "0.0.2", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(6, result.getMessages().size());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName06");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+
+        result = apexModel.deletePolicyStateFinalizerLogic(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.2", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", null, "SomeState", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("zooby", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("zooby", null, "looby", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("zooby", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", null, "looby", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.2", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName06");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName06");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName06");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(5, result.getMessages().size());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName02");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName02");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName02");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+        result = apexModel.deletePolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName02",
+            "UNDEFINED", "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName03", "MVEL",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName04", "JAVA",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", "0.0.1", "TestState1", "SFLName05", "JYTHON",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName06",
+            "JAVASCRIPT", "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateFinalizerLogic("MyTestPolicy", null, "TestState1", "SFLName07", "JRUBY",
+            "Some Policy Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createTask("TestTask0", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("TestTask1", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("TestTask2", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("TestTask3", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("TestTask4", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createPolicyStateTaskRef(null, null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, null, null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "SomeState", null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "SomeState", null, null, null, null,
+            "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "1.2.3", "SomeState", null, null, null, null,
+            "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("AnyOldPolicy", "1.2.3", "SomeState", null, null, null, null,
+            "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName", null,
+            null, null, "DummyOutput");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName",
+            "SomeTask", "Zooby|", null, "DummyOutput");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName",
+            "SomeTask", "0.0.1", null, "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", null, "DummyOutput");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "Some Policy Logic", "DummyOutput");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "DIRECT", "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "LOGIC", "DummyOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "DIRECT", "SFLName07");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "LOGIC", "SomeOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "DIRECT", "SomeOutput");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "NonExistantTask", "0.0.1", "DIRECT", "SomeOutput");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName", "task",
+            "0.0.1", "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask0", "0.0.1", "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask1", "0.0.1", "DIRECT", "SomeOtherOutput");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask2", "0.0.1", "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask3", "0.0.1", "DIRECT", "SomeOtherOutput");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, "TestTask4", "0.0.1",
+            "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, "TestTask4", "0.0.1",
+            "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, "TestState1", "TestTask4", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask4", "0.0.1", "FUNKY", "SFLName07");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask4", "0.0.1", "UNDEFINED", "SFLName07");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeTaskLocalName",
+            "TestTask4", "0.0.1", "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, "TestTask0", "0.0.1",
+            "LOGIC", "SFLName07");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.listPolicyStateTaskRef(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("zooby", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("zooby", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("zooby", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(12, result.getMessages().size());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "SomeOldTask", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "task", "1.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", "task", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.deletePolicyStateTaskRef(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("zooby", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("zooby", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("zooby", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "ADummyTask", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", "0.0.1", "TestState1", "task", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(12, result.getMessages().size());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, "TestState1", "TestTask0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(10, result.getMessages().size());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, "TestState1", "TestTask2", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(8, result.getMessages().size());
+        result = apexModel.deletePolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(4, result.getMessages().size());
+        result = apexModel.listPolicyStateTaskRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createPolicyStateContextRef(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "1.2.3", "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("AnyOldPolicy", "1.2.3", "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTask", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTask", "Zooby|");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "SomeTask", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "task", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyPolicy123", null, null, "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyPolicy123", null, "TestState1", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "4.5.6", "TestState1", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.1.4", "TestState1", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", null, "TestState1", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.listPolicyStateContextRef(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateContextRef("zooby", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateContextRef("zooby", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("zooby", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "AContextMap04", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "1.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deletePolicyStateContextRef(null, null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "SomeState", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.1", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("zooby", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("zooby", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("zooby", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "looby", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.2", "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "ADummyContextMap", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "AContextMap04", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "TestState1", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "TestState1", "contextAlbum0", "0.1.5");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "TestState1", "contextAlbum1", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.createPolicyStateContextRef("MyTestPolicy", "0.0.1", "TestState1", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deletePolicyStateContextRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listPolicyStateContextRef("MyTestPolicy", null, "TestState1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deletePolicy(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(3, result.getMessages().size());
+
+        result = apexModel.listPolicy(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(0, result.getMessages().size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiTaskTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiTaskTest.java
new file mode 100644
index 000000000..15e53f925
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexEditorApiTaskTest.java
@@ -0,0 +1,376 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.modelapi.impl.ApexModelImpl;
+
+/**
+ * Test tasks for API tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexEditorApiTaskTest {
+    @Test
+    public void testTaskCrud() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.validateTask(null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.validateTask("%%%$£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.createTask("@^^$^^$", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createTask("MyTask002", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("MyTask002", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createTask("MyTask012", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("MyTask012", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.listTask(null, null);
+        result = apexModel.createTask("MyTask002", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createTask("MyTask012", "0.1.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deleteTask("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTask("MyTask002", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.validateTask(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateTask("@$$$£", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updateTask("MyTask002", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTask("MyTask002", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateTask("MyTask002", "0.0.2", "1fa2e430-f2b2-11e6-bc64-92361f002700",
+            "A description of 002");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTask("MyTask012", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTask("MyTask012", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTask("MyTask012", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTask("MyTask015", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateTask("MyTask014", "0.1.5", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listTask("£@£@@£@£", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listTask(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTask("MyTask012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTask("MyTask012", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTask("MyTask012", "0.2.5");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listTask("MyTask014", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteTask("@£££@", "0.1.1");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deleteTask("MyTask012", "0.1.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deleteTask("MyTask012oooo", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listTask("MyTask012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.deleteTask("MyTask012", "0.1.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listTask("MyTask012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+
+        result = apexModel.deleteTask("MyTask012", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.listTask("MyTask012", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.updateTaskLogic("MyTask002", null, "NewLogic00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskLogic("MyTask123", null, "NewLogic00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "4.5.6", "NewLogic00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "0.1.4", "NewLogic00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "0.0.2", "NewLogic00", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "0.0.2", "UNDEFINED", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "0.0.2", "MVEL", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "0.0.2", "JAVA", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", "0.0.2", "JYTHON", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", null, "JAVASCRIPT", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskLogic("MyTask002", null, "JRUBY", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.updateTaskLogic("MyTask002", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask002", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask002", "0.0.2", "", "Some Other Task Logic");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask002", "0.0.2", "MVEL", "Some Other Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask012", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask002", null, null, "Some Other Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask002", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask015", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.updateTaskLogic("MyTask014", "0.1.5", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.listTaskLogic("MyTask002", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskLogic("MyTask002", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskLogic(null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteTaskLogic("@£@£@£", "0.0.2");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deleteTaskLogic("NonExistantTask", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        assertEquals(1, apexModel.listTaskLogic("MyTask002", null).getMessages().size());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskLogic("MyTask002", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(1, apexModel.listTaskLogic("MyTask002", null).getMessages().size());
+        result = apexModel.createTaskLogic("MyTask002", null, "JRUBY", "Some Task Logic");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskLogic("MyTask002", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.deleteTaskLogic("MyTask002", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskField("MyTask002", "0.0.2", "NewField00", "eventContextItem0", null, false);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(ApexModelImpl.FIELDS_DEPRECATED_WARN_MSG, result.getMessage().trim());
+        result = apexModel.handleTaskField("MyTask002", "0.0.2", "NewField01");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(ApexModelImpl.FIELDS_DEPRECATED_WARN_MSG, result.getMessage().trim());
+
+        result = apexModel.createTaskParameter("MyTask123", null, "NewPar00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskParameter("MyTask002", "4.5.6", "NewPar00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskParameter("MyTask002", "0.1.4", "NewPar00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar00", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar00", "eventContextItem0");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar00", "eventContextItem0");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar01", "eventContextItem0");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar02", "eventContextItem0");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar02", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", "0.0.2", "NewPar03", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createTaskParameter("MyTask002", null, null, "Default value");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.listTaskParameter("@£$%", null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", "0.0.3", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", "0.0.2", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", "0.0.2", "NewPar01");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", "0.0.2", "NewPar02");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteTaskParameter("@£$%", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deleteTaskParameter("NonExistantTask", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(3, apexModel.listTaskParameter("MyTask002", null, null).getMessages().size());
+        result = apexModel.deleteTaskParameter("MyTask002", "0.0.2", "NewPar04");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(3, apexModel.listTaskParameter("MyTask002", null, null).getMessages().size());
+        result = apexModel.deleteTaskParameter("MyTask002", null, "NewPar02");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, apexModel.listTaskParameter("MyTask002", null, null).getMessages().size());
+        result = apexModel.deleteTaskParameter("MyTask002", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.listTaskParameter("MyTask002", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deleteTaskParameter("MyTask002", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskContextRef("@£$$", null, "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask123", null, "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask123", null, "AContextMap00", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask123", null, "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "4.5.6", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.1.4", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "AContextMap00", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "contextAlbum2", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "contextAlbum1", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = apexModel.createTaskContextRef("MyTask002", null, "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.listTaskContextRef("@£$%", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.listTaskContextRef("MyTask002", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "AContextMap04", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "contextAlbum0", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "contextAlbum1", "0.0.1");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", "0.0.2", "contextAlbum1", "0.0.2");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteTaskContextRef("@£$%", "0.0.2", "AContextMap04", null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        result = apexModel.deleteTaskContextRef("NonExistantTask", "0.0.2", "AContextMap04", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        assertEquals(2, apexModel.listTaskContextRef("MyTask002", null, null, null).getMessages().size());
+        result = apexModel.deleteTaskContextRef("MyTask002", "0.0.2", "AContextMap04", null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deleteTaskContextRef("MyTask002", null, "contextAlbum0", "0.0.3");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deleteTaskContextRef("MyTask002", null, "contextAlbum0", "0.1.5");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+        result = apexModel.deleteTaskContextRef("MyTask002", null, "contextAlbum0", null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.deleteTaskContextRef("MyTask002", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(1, result.getMessages().size());
+        result = apexModel.listTaskContextRef("MyTask002", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = apexModel.deleteTask(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(2, result.getMessages().size());
+
+        result = apexModel.listTask(null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertEquals(0, result.getMessages().size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexModelApiTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexModelApiTest.java
new file mode 100644
index 000000000..f28d0e634
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ApexModelApiTest.java
@@ -0,0 +1,208 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.File;
+import java.io.IOException;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.util.UUID;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.modelapi.impl.ApexModelImpl;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+/**
+ * Test the apex model API.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexModelApiTest {
+    private Connection connection;
+
+    @Before
+    public void setup() throws Exception {
+        // Hold the h2 database up for entire tests
+        connection = DriverManager.getConnection("jdbc:h2:mem:testdb");
+    }
+
+    @After
+    public void teardown() throws Exception {
+        // Close the h2 database after tests
+        connection.close();
+    }
+
+    @Test
+    public void testApexModelLoadFromFile() {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.loadFromFile("src/main/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.junk");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        assertEquals("Unable to unmarshal Apex concept", result.getMessages().get(0).trim());
+    }
+
+    @Test
+    public void testApexModelSaveToFile() throws IOException {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = apexModel.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        final File tempJsonModelFile = File.createTempFile("ApexModelTest", ".json");
+        result = apexModel.saveToFile(tempJsonModelFile.getPath());
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        final ApexModel jsonApexModel = new ApexModelFactory().createApexModel(null);
+        result = jsonApexModel.loadFromFile(tempJsonModelFile.getPath());
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        tempJsonModelFile.delete();
+
+        final File tempModelFile = File.createTempFile("ApexModelTest", ".json");
+        result = apexModel.saveToFile(tempModelFile.getPath());
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        final ApexModel testApexModel = new ApexModelFactory().createApexModel(null);
+        result = testApexModel.loadFromFile(tempModelFile.getPath());
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        tempModelFile.delete();
+    }
+
+    @Test
+    public void testApexModelUrl() throws IOException {
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        assertThatThrownBy(() -> apexModel.readFromUrl(null)).isInstanceOf(IllegalArgumentException.class);
+        assertThatThrownBy(() -> apexModel.writeToUrl(null)).isInstanceOf(IllegalArgumentException.class);
+        ApexApiResult result = null;
+        result = apexModel.readFromUrl("zooby/looby");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.writeToUrl("zooby/looby");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.readFromUrl("zooby://zooby/looby");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.writeToUrl("zooby://zooby/looby");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        final File tempJsonModelFile = File.createTempFile("ApexModelTest", "json");
+
+        result = apexModel.saveToFile(tempJsonModelFile.getPath());
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        final String tempFileUrlString = tempJsonModelFile.toURI().toString();
+        result = apexModel.readFromUrl(tempFileUrlString);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.writeToUrl(tempFileUrlString);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+        assertEquals("protocol doesn't support output", result.getMessages().get(0));
+
+        tempJsonModelFile.delete();
+    }
+
+    @Test
+    public void testApexModelMisc() throws IOException {
+        final ApexModelImpl apexModelImpl = (ApexModelImpl) new ApexModelFactory().createApexModel(null);
+
+        ApexApiResult result = null;
+
+        result = apexModelImpl.getModelKey();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.listModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.createModel("ModelName", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.updateModel("ModelName", "0.0.1", UUID.randomUUID().toString(), "Model Description");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        apexModelImpl.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        final String modelString = TextFileUtils.getTextFileAsString("src/test/resources/models/PolicyModel.json");
+        result = apexModelImpl.loadFromString(modelString);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        final File tempFile = File.createTempFile("ApexModel", "json");
+        tempFile.deleteOnExit();
+        TextFileUtils.putStringAsFile(modelString, tempFile);
+
+        apexModelImpl.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.loadFromFile(tempFile.getPath());
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.analyse();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.validate();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.compare(tempFile.getPath(), true, true);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.compareWithString(modelString, true, true);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.split("policy");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.split(tempFile.getPath(), "policy");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.merge(tempFile.getPath(), true);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModelImpl.mergeWithString(modelString, true);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        assertNotEquals(0, apexModelImpl.hashCode());
+        assertNotNull(apexModelImpl.getCopy());
+        assertNotNull(apexModelImpl.build());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ModelFacadeTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ModelFacadeTest.java
new file mode 100644
index 000000000..d3b32b923
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ModelFacadeTest.java
@@ -0,0 +1,99 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.Properties;
+import java.util.UUID;
+import org.junit.Test;
+import org.onap.policy.apex.model.modelapi.impl.ModelFacade;
+
+public class ModelFacadeTest {
+
+    @Test
+    public void testModelFacade() {
+        assertThatThrownBy(() -> new ModelFacade(null, null))
+            .hasMessage("apexModel may not be null");
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        assertThatThrownBy(() -> new ModelFacade(apexModel, null))
+            .hasMessage("apexProperties may not be null");
+        final Properties modelProperties = new Properties();
+        final ModelFacade mf = new ModelFacade(apexModel, modelProperties);
+
+        ApexApiResult result = mf.createModel(null, null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mf.createModel("ModelName", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mf.createModel("ModelName", "0.0.1", null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        modelProperties.setProperty("DEFAULT_CONCEPT_VERSION", "");
+        result = mf.createModel("ModelName", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        modelProperties.setProperty("DEFAULT_CONCEPT_VERSION", "£$£$£$");
+        result = mf.createModel("ModelName", null, null, null);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        modelProperties.setProperty("DEFAULT_CONCEPT_VERSION", "0.0.1");
+        result = mf.createModel("ModelName", null, null, null);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+        result = mf.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = mf.createModel("ModelName", null, null, null);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mf.updateModel("ModelName", null, UUID.randomUUID().toString(), "New Description");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mf.updateModel("ModelName", "0.0.1", UUID.randomUUID().toString(), "New Description");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        modelProperties.remove("DEFAULT_CONCEPT_VERSION");
+        result = mf.updateModel("ModelName", null, UUID.randomUUID().toString(), "New Description");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mf.updateModel(null, null, UUID.randomUUID().toString(), "New Description");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mf.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = mf.updateModel("name", "0.0.1", UUID.randomUUID().toString(), "New Description");
+        assertEquals(ApexApiResult.Result.CONCEPT_DOES_NOT_EXIST, result.getResult());
+
+        result = mf.getModelKey();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mf.listModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mf.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        assertNotNull(mf);
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/ModelHandlerFacadeTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/ModelHandlerFacadeTest.java
new file mode 100644
index 000000000..5bbc95992
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/ModelHandlerFacadeTest.java
@@ -0,0 +1,128 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Properties;
+import org.junit.Test;
+import org.onap.policy.apex.model.modelapi.impl.ModelHandlerFacade;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+/**
+ * Test the model handler facade.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ModelHandlerFacadeTest {
+
+    @Test
+    public void testModelHandlerFacade() throws IOException {
+        assertThatThrownBy(() -> new ModelHandlerFacade(null, null))
+            .hasMessage("apexModel may not be null");
+        final ApexModel apexModel = new ApexModelFactory().createApexModel(null);
+
+        assertThatThrownBy(() -> new ModelHandlerFacade(apexModel, null))
+            .hasMessage("apexProperties may not be null");
+        final Properties modelProperties = new Properties();
+        final ModelHandlerFacade mhf = new ModelHandlerFacade(apexModel, modelProperties);
+        assertNotNull(mhf);
+
+        ApexApiResult result = mhf.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mhf.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        final String modelString = TextFileUtils.getTextFileAsString("src/test/resources/models/PolicyModel.json");
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mhf.loadFromString(modelString);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mhf.loadFromString(modelString);
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mhf.readFromUrl("blah://somewhere/over/the/rainbow");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.loadFromString(modelString);
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mhf.readFromUrl("http://somewhere/over/the/rainbow");
+        assertEquals(ApexApiResult.Result.CONCEPT_EXISTS, result.getResult());
+
+        final File tempFile = File.createTempFile("ApexModel", "json");
+        tempFile.deleteOnExit();
+
+        result = mhf.writeToUrl("File:///" + tempFile.getCanonicalPath());
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.validate();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = mhf.validate();
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.compare("src/test/resources/models/NonExistant.json", true, true);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.compareWithString("zooby", true, true);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.split("FailSplit", "NonExistantPolicy");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.split("NonExistantPolicy");
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.merge("src/test/resources/models/NonExistant.json", false);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = mhf.merge("src/test/resources/models/PolicyModel.json", false);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = mhf.loadFromFile("src/test/resources/models/PolicyModel.json");
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+
+        result = mhf.mergeWithString("@£@$@£", true);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+
+        result = apexModel.deleteModel();
+        assertEquals(ApexApiResult.Result.SUCCESS, result.getResult());
+        result = mhf.mergeWithString(modelString, false);
+        assertEquals(ApexApiResult.Result.FAILED, result.getResult());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/modelapi/RealModelTest.java b/model/src/test/java/org/onap/policy/apex/model/modelapi/RealModelTest.java
new file mode 100644
index 000000000..2a29f5297
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/modelapi/RealModelTest.java
@@ -0,0 +1,46 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import static org.junit.Assert.assertTrue;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import java.util.Map;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelCustomGsonMapAdapter;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelReader;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+public class RealModelTest {
+    @Test
+    public void testRealModel() throws Exception {
+
+        final String modelString = TextFileUtils.getTextFileAsString("src/test/resources/models/PolicyModel.json");
+
+        AxPolicyModel policyModel = new ApexModelReader<AxPolicyModel>(AxPolicyModel.class).read(modelString);
+
+        AxValidationResult result = new AxValidationResult();
+        assertTrue(policyModel.validate(result).isValid());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/DummyLogicReader.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/DummyLogicReader.java
new file mode 100644
index 000000000..007288343
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/DummyLogicReader.java
@@ -0,0 +1,65 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+public class DummyLogicReader implements AxLogicReader {
+
+    /**
+     * {@inheritDoc}.
+     */
+    @Override
+    public String getLogicPackage() {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}.
+     */
+    @Override
+    public AxLogicReader setLogicPackage(final String logicPackage) {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}.
+     */
+    @Override
+    public String getDefaultLogic() {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}.
+     */
+    @Override
+    public AxLogicReader setDefaultLogic(final String defaultLogic) {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}.
+     */
+    @Override
+    public String readLogic(final AxLogic axLogic) {
+        return "Dummy Logic";
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/ExceptionsTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/ExceptionsTest.java
new file mode 100644
index 000000000..0afb48b3c
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/ExceptionsTest.java
@@ -0,0 +1,51 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/**
+ * Test model exceptions.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ExceptionsTest {
+
+    @Test
+    public void test() {
+        assertNotNull(new PolicyException("Message"));
+        assertNotNull(new PolicyException("Message", new IOException()));
+
+        final PolicyException ae = new PolicyException("Message", new IOException("IO exception message"));
+        assertEquals("Message\ncaused by: Message\ncaused by: IO exception message", ae.getCascadedMessage());
+
+        assertNotNull(new PolicyRuntimeException("Message"));
+        assertNotNull(new PolicyRuntimeException("Message", new IOException()));
+
+        final PolicyRuntimeException re =
+                new PolicyRuntimeException("Runtime Message", new IOException("IO runtime exception message"));
+        assertEquals("Runtime Message\ncaused by: Runtime Message\ncaused by: IO runtime exception message",
+                re.getCascadedMessage());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/LogicTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/LogicTest.java
new file mode 100644
index 000000000..fbfc7c4a0
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/LogicTest.java
@@ -0,0 +1,161 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test apex logic.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class LogicTest {
+
+    @Test
+    public void testLogic() {
+        final DummyLogicReader logicReader = new DummyLogicReader();
+
+        assertNotNull(new AxLogic());
+        assertNotNull(new AxLogic(new AxReferenceKey()));
+        assertNotNull(new AxLogic(new AxReferenceKey(), "LogicFlavour", "Logic"));
+        assertNotNull(new AxLogic(new AxReferenceKey(), "LogicName", "LogicFlavour", "Logic"));
+        assertNotNull(new AxLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+
+        assertNotNull(new AxTaskLogic());
+        assertNotNull(new AxTaskLogic(new AxReferenceKey()));
+        assertNotNull(new AxTaskLogic(new AxReferenceKey(), "LogicFlavour", "Logic"));
+        assertNotNull(new AxTaskLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+        assertNotNull(new AxTaskLogic(new AxLogic()));
+        assertNotNull(new AxTaskLogic(new AxArtifactKey(), "LogicName", "LogicFlavour", logicReader));
+        assertNotNull(new AxTaskLogic(new AxArtifactKey(), "LogicName", "LogicFlavour", "Logic"));
+        assertNotNull(new AxTaskLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+
+        assertNotNull(new AxTaskSelectionLogic());
+        assertNotNull(new AxTaskSelectionLogic(new AxReferenceKey()));
+        assertNotNull(new AxTaskSelectionLogic(new AxReferenceKey(), "LogicFlavour", "Logic"));
+        assertNotNull(new AxTaskSelectionLogic(new AxReferenceKey(), "LogicName", "LogicFlavour", "Logic"));
+        assertNotNull(new AxTaskSelectionLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+        assertNotNull(new AxTaskSelectionLogic(new AxLogic()));
+        assertNotNull(new AxTaskSelectionLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+        assertNotNull(new AxTaskSelectionLogic(new AxReferenceKey(), "LogicName", "LogicFlavour", logicReader));
+
+        assertNotNull(new AxStateFinalizerLogic());
+        assertNotNull(new AxStateFinalizerLogic(new AxReferenceKey()));
+        assertNotNull(new AxStateFinalizerLogic(new AxReferenceKey(), "LogicFlavour", "Logic"));
+        assertNotNull(new AxStateFinalizerLogic(new AxReferenceKey(), "LogicName", "LogicFlavour", "Logic"));
+        assertNotNull(new AxStateFinalizerLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+        assertNotNull(new AxStateFinalizerLogic(new AxLogic()));
+        assertNotNull(new AxStateFinalizerLogic(new AxReferenceKey(), "LogicFlavour", logicReader));
+        assertNotNull(new AxStateFinalizerLogic(new AxReferenceKey(), "LogicName", "LogicFlavour", logicReader));
+
+        final AxLogic logic = new AxLogic();
+
+        final AxReferenceKey logicKey = new AxReferenceKey("LogicParentName", "0.0.1", "PLN", "LN");
+        logic.setKey(logicKey);
+        assertEquals("LogicParentName:0.0.1:PLN:LN", logic.getKey().getId());
+        assertEquals("LogicParentName:0.0.1:PLN:LN", logic.getKeys().get(0).getId());
+
+        logic.setLogicFlavour("LogicFlavour");
+        assertEquals("LogicFlavour", logic.getLogicFlavour());
+
+        logic.setLogic("Logic");
+        assertEquals("Logic", logic.getLogic());
+
+        AxValidationResult result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        logic.setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        logic.setKey(logicKey);
+        result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        assertThatThrownBy(() -> logic.setLogicFlavour(null))
+            .hasMessageContaining("parameter \"logicFlavour\" is null");
+        assertThatThrownBy(() -> logic.setLogicFlavour(""))
+            .hasMessage("parameter \"logicFlavour\": value \"\", "
+                    + "does not match regular expression \"[A-Za-z0-9\\-_]+\"");
+        logic.setLogicFlavour(AxLogic.LOGIC_FLAVOUR_UNDEFINED);
+        result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        logic.setLogicFlavour("LogicFlavour");
+        result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        assertThatThrownBy(() -> logic.setLogic(null)).hasMessage("logic may not be null");
+        logic.setLogic("");
+        result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        logic.setLogic("Logic");
+        result = new AxValidationResult();
+        result = logic.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        logic.clean();
+
+        final AxLogic clonedLogic = new AxLogic(logic);
+        assertEquals("AxLogic:(key=AxReferenceKey:(parentKeyName=LogicParentName,parentKeyVersion=0.0.1,"
+                        + "parentLocalName=PLN,localName=LN),logicFlavour=LogicFlavour,logic=Logic)",
+                        clonedLogic.toString());
+
+        assertNotEquals(0, logic.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(logic, logic); // NOSONAR
+        assertEquals(logic, clonedLogic);
+        assertNotNull(logic);
+        assertNotEquals(logic, (Object) "Hello");
+        assertNotEquals(logic, new AxLogic(AxReferenceKey.getNullKey(), "LogicFlavour", "Logic"));
+        assertNotEquals(logic, new AxLogic(logicKey, "AnotherLogicFlavour", "Logic"));
+        assertNotEquals(logic, new AxLogic(logicKey, "LogicFlavour", "AnotherLogic"));
+        assertEquals(logic, new AxLogic(logicKey, "LogicFlavour", "Logic"));
+
+        assertEquals(0, logic.compareTo(logic));
+        assertEquals(0, logic.compareTo(clonedLogic));
+        assertNotEquals(0, logic.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, logic.compareTo(null));
+        assertNotEquals(0, logic.compareTo(new AxLogic(AxReferenceKey.getNullKey(), "LogicFlavour", "Logic")));
+        assertNotEquals(0, logic.compareTo(new AxLogic(logicKey, "AnotherLogicFlavour", "Logic")));
+        assertNotEquals(0, logic.compareTo(new AxLogic(logicKey, "LogicFlavour", "AnotherLogic")));
+        assertEquals(0, logic.compareTo(new AxLogic(logicKey, "LogicFlavour", "Logic")));
+
+        assertNotNull(logic.getKeys());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/PoliciesTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/PoliciesTest.java
new file mode 100644
index 000000000..526f5a628
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/PoliciesTest.java
@@ -0,0 +1,391 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.Map;
+import java.util.TreeMap;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+import org.onap.policy.apex.model.policymodel.handling.SupportApexPolicyModelCreator;
+
+/**
+ * Test apex policies.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class PoliciesTest {
+
+    @Test
+    public void testPolicies() {
+        final TreeMap<String, AxState> stateMap = new TreeMap<>();
+        final TreeMap<String, AxState> stateMapEmpty = new TreeMap<>();
+
+        assertNotNull(new AxPolicy());
+        assertNotNull(new AxPolicy(new AxArtifactKey()));
+        assertNotNull(new AxPolicy(new AxArtifactKey(), "PolicyTemplate", stateMapEmpty, "FirstState"));
+
+        final AxPolicy policy = new AxPolicy();
+
+        final AxArtifactKey policyKey = new AxArtifactKey("PolicyName", "0.0.1");
+
+        final AxState firstState = new AxState(new AxReferenceKey(policy.getKey(), "FirstState"));
+        final AxState badState = new AxState(new AxReferenceKey(policy.getKey(), "BadState"));
+        final AxStateOutput badStateOutput = new AxStateOutput(badState.getKey(), AxArtifactKey.getNullKey(),
+                        new AxReferenceKey(policyKey, "BadNextState"));
+        badState.getStateOutputs().put(badStateOutput.getKey().getLocalName(), badStateOutput);
+        stateMap.put(firstState.getKey().getLocalName(), firstState);
+
+        assertThatThrownBy(() -> policy.setKey(null))
+            .hasMessage("key may not be null");
+        policy.setKey(policyKey);
+        assertEquals("PolicyName:0.0.1", policy.getKey().getId());
+        assertEquals("PolicyName:0.0.1", policy.getKeys().get(0).getId());
+
+        assertThatThrownBy(() -> policy.setTemplate(null))
+            .hasMessage("template may not be null");
+        policy.setTemplate("PolicyTemplate");
+        assertEquals("PolicyTemplate", policy.getTemplate());
+
+        assertThatThrownBy(() -> policy.setStateMap(null))
+            .hasMessage("stateMap may not be null");
+        policy.setStateMap(stateMap);
+        assertEquals(stateMap, policy.getStateMap());
+
+        assertThatThrownBy(() -> policy.setFirstState(null))
+            .hasMessage("firstState may not be null");
+        policy.setFirstState("FirstState");
+        assertEquals("FirstState", policy.getFirstState());
+
+        assertEquals("PolicyName:0.0.1", policy.getKeys().get(0).getId());
+
+        final AxPolicy policyPN = new SupportApexPolicyModelCreator().getModel().getPolicies().get("policy");
+
+        AxValidationResult result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxArtifactKey savedPolicyKey = policyPN.getKey();
+        policyPN.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policyPN.setKey(savedPolicyKey);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final String savedTemplate = policyPN.getTemplate();
+        policyPN.setTemplate("");
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.OBSERVATION, result.getValidationResult());
+
+        policyPN.setTemplate(savedTemplate);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final Map<String, AxState> savedStateMap = policyPN.getStateMap();
+
+        policyPN.setStateMap(stateMapEmpty);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policyPN.setStateMap(savedStateMap);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        savedStateMap.put(AxKey.NULL_KEY_NAME, firstState);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        savedStateMap.remove(AxKey.NULL_KEY_NAME);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        savedStateMap.put("NullState", null);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        savedStateMap.remove("NullState");
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        savedStateMap.put("BadStateKey", firstState);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        savedStateMap.remove("BadStateKey");
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        savedStateMap.put(badState.getKey().getLocalName(), badState);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        savedStateMap.remove(badState.getKey().getLocalName());
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final String savedFirstState = policyPN.getFirstState();
+
+        policyPN.setFirstState("");
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policyPN.setFirstState(savedFirstState);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        policyPN.setFirstState("NonExistantFirstState");
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policyPN.setFirstState(savedFirstState);
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxState clonedState = new AxState(policyPN.getStateMap().get("state"));
+        clonedState.getKey().setLocalName("ClonedState");
+
+        savedStateMap.put(clonedState.getKey().getLocalName(), clonedState);
+        policyPN.buildReferences();
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.WARNING, result.getValidationResult());
+
+        savedStateMap.remove(clonedState.getKey().getLocalName());
+        result = new AxValidationResult();
+        result = policyPN.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        policyPN.clean();
+
+        final AxPolicy clonedPolicy = new AxPolicy(policyPN);
+        assertEquals("AxPolicy:(key=AxArtifactKey:(name=policy,version=0.0.1),template=FREEFORM,sta",
+                        clonedPolicy.toString().substring(0, 77));
+
+        assertNotEquals(0, policyPN.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(policyPN, policyPN); // NOSONAR
+        assertEquals(policyPN, clonedPolicy);
+        assertNotNull(policyPN);
+
+        Object helloObj = "Hello";
+        assertNotEquals(policyPN, helloObj);
+        assertNotEquals(policyPN,
+                        new AxPolicy(AxArtifactKey.getNullKey(), savedTemplate, savedStateMap, savedFirstState));
+        assertNotEquals(policyPN, new AxPolicy(savedPolicyKey, "SomeTemplate", savedStateMap, savedFirstState));
+        assertNotEquals(policyPN, new AxPolicy(savedPolicyKey, savedTemplate, stateMapEmpty, savedFirstState));
+        assertNotEquals(policyPN, new AxPolicy(savedPolicyKey, savedTemplate, savedStateMap, "SomeFirstState"));
+        assertEquals(policyPN, new AxPolicy(savedPolicyKey, savedTemplate, savedStateMap, savedFirstState));
+
+        assertEquals(0, policyPN.compareTo(policyPN));
+        assertEquals(0, policyPN.compareTo(clonedPolicy));
+        assertNotEquals(0, policyPN.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, policyPN.compareTo(null));
+        assertNotEquals(0, policyPN.compareTo(
+                        new AxPolicy(AxArtifactKey.getNullKey(), savedTemplate, savedStateMap, savedFirstState)));
+        assertNotEquals(0, policyPN.compareTo(new AxPolicy(savedPolicyKey,
+                "SomeTemplate", savedStateMap, savedFirstState)));
+        assertNotEquals(0, policyPN.compareTo(new AxPolicy(savedPolicyKey, savedTemplate,
+                stateMapEmpty, savedFirstState)));
+        assertNotEquals(0, policyPN.compareTo(new AxPolicy(savedPolicyKey, savedTemplate,
+                savedStateMap, "SomeFirstState")));
+        assertEquals(0, policyPN.compareTo(new AxPolicy(savedPolicyKey, savedTemplate,
+                savedStateMap, savedFirstState)));
+
+        assertNotNull(policyPN.getKeys());
+
+        final AxPolicies policies = new AxPolicies();
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        // Invalid, no events in event map
+        policies.setKey(new AxArtifactKey("PoliciesKey", "0.0.1"));
+        assertEquals("PoliciesKey:0.0.1", policies.getKey().getId());
+
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policies.getPolicyMap().put(savedPolicyKey, policyPN);
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        policies.getPolicyMap().put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policies.getPolicyMap().remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        policies.getPolicyMap().put(new AxArtifactKey("NullValueKey", "0.0.1"), null);
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policies.getPolicyMap().remove(new AxArtifactKey("NullValueKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        policies.getPolicyMap().put(new AxArtifactKey("BadEventKey", "0.0.1"), policyPN);
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        policies.getPolicyMap().remove(new AxArtifactKey("BadEventKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = policies.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        policies.clean();
+
+        final AxPolicies clonedPolicies = new AxPolicies(policies);
+        assertEquals("AxPolicies:(key=AxArtifactKey:(name=PoliciesKey,version=0.0.",
+                        clonedPolicies.toString().substring(0, 60));
+
+        assertNotEquals(0, policies.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(policies, policies); // NOSONAR
+        assertEquals(policies, clonedPolicies);
+        assertNotNull(policies);
+        assertNotEquals(policyPN, helloObj);
+        assertNotEquals(policies, new AxPolicies(new AxArtifactKey()));
+
+        assertEquals(0, policies.compareTo(policies));
+        assertEquals(0, policies.compareTo(clonedPolicies));
+        assertNotEquals(0, policies.compareTo(null));
+        assertNotEquals(0, policies.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, policies.compareTo(new AxPolicies(new AxArtifactKey())));
+
+        clonedPolicies.get(savedPolicyKey).setTemplate("AnotherTemplate");
+        assertNotEquals(0, policies.compareTo(clonedPolicies));
+
+        assertEquals(policies.getKey(), policies.getKeys().get(0));
+
+        assertEquals("policy", policies.get("policy").getKey().getName());
+        assertEquals("policy", policies.get("policy", "0.0.1").getKey().getName());
+        assertEquals(1, policies.getAll("policy", "0.0.1").size());
+        assertEquals(0, policies.getAll("NonExistantPolicy").size());
+
+        AxStateTree stateTree = policy.getStateTree();
+        assertNotNull(stateTree);
+        assertNotNull(stateTree.getReferencedStateList());
+        assertNotNull(stateTree.getReferencedStateSet());
+
+        final AxState secondState = new AxState(policyPN.getStateMap().get("state"));
+        secondState.getKey().setLocalName("SecondState");
+        policyPN.getStateMap().put("SecondState", secondState);
+        policyPN.getStateMap().get("state").getStateOutputs().get("stateOutput0").setNextState(secondState.getKey());
+
+        stateTree = policyPN.getStateTree();
+        assertNotNull(stateTree);
+        assertNotNull(stateTree.getReferencedStateList());
+        assertNotNull(stateTree.getReferencedStateSet());
+        assertNotNull(stateTree.getNextStates());
+
+        policyPN.getStateMap().get("SecondState").getStateOutputs().get("stateOutput0")
+                        .setNextState(policyPN.getStateMap().get("state").getKey());
+        assertThatThrownBy(() -> policyPN.getStateTree())
+            .hasMessageContaining("loop detected in state tree for policy policy:0.0.1 state SecondState, "
+                + "next state state referenced more than once");
+        policyPN.getStateMap().get("SecondState").getStateOutputs().get("stateOutput0")
+                        .setNextState(AxReferenceKey.getNullKey());
+
+        final AxState thirdState = new AxState(policyPN.getStateMap().get("state"));
+        thirdState.getKey().setLocalName("ThirdState");
+        policyPN.getStateMap().put("ThirdState", thirdState);
+        policyPN.getStateMap().get("SecondState").getStateOutputs().get("stateOutput0")
+                        .setNextState(thirdState.getKey());
+        policyPN.getStateMap().get("ThirdState").getStateOutputs().get("stateOutput0")
+                        .setNextState(AxReferenceKey.getNullKey());
+
+        stateTree = policyPN.getStateTree();
+
+        final AxStateOutput ssS0Clone = new AxStateOutput(
+                        policyPN.getStateMap().get("SecondState").getStateOutputs().get("stateOutput0"));
+        ssS0Clone.getKey().setLocalName("ssS0Clone");
+        policyPN.getStateMap().get("SecondState").getStateOutputs().put("ssS0Clone", ssS0Clone);
+
+        assertThatThrownBy(() -> policyPN.getStateTree())
+            .hasMessageContaining("loop detected in state tree for policy policy:0.0.1 state SecondState, "
+                + "next state ThirdState referenced more than once");
+        policyPN.getStateMap().get("SecondState").getStateOutputs().remove("ssS0Clone");
+
+        policyPN.getStateMap().get("state").getStateOutputs().get("stateOutput0").setNextState(secondState.getKey());
+        secondState.getStateOutputs().get("stateOutput0").setNextState(thirdState.getKey());
+        thirdState.getStateOutputs().get("stateOutput0").setNextState(AxReferenceKey.getNullKey());
+
+        stateTree = policyPN.getStateTree();
+        assertNotNull(stateTree.getState());
+
+        thirdState.getStateOutputs().get("stateOutput0").setNextState(secondState.getKey());
+
+        assertThatThrownBy(() -> policyPN.getStateTree())
+            .hasMessageContaining("loop detected in state tree for policy policy:0.0.1 state ThirdState, "
+                            + "next state SecondState referenced more than once");
+        thirdState.getStateOutputs().get("stateOutput0").setNextState(AxReferenceKey.getNullKey());
+
+        stateTree = policyPN.getStateTree();
+
+        final AxStateTree otherStateTree = policyPN.getStateTree();
+        assertEquals(0, stateTree.compareTo(otherStateTree));
+
+        for (final AxStateTree childStateTree : stateTree.getNextStates()) {
+            assertNotEquals(0, stateTree.compareTo(childStateTree));
+        }
+
+        otherStateTree.getNextStates().clear();
+        assertNotEquals(0, stateTree.compareTo(otherStateTree));
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/PolicyModelTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/PolicyModelTest.java
new file mode 100644
index 000000000..b699b5d48
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/PolicyModelTest.java
@@ -0,0 +1,312 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvents;
+import org.onap.policy.apex.model.eventmodel.concepts.AxField;
+import org.onap.policy.apex.model.policymodel.handling.SupportApexPolicyModelCreator;
+
+/**
+ * Test policy models.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class PolicyModelTest {
+
+    @Test
+    public void testPolicyModel() {
+        assertNotNull(new AxPolicyModel());
+        assertNotNull(new AxPolicyModel(new AxArtifactKey()));
+        assertNotNull(new AxPolicyModel(new AxArtifactKey(), new AxContextSchemas(), new AxKeyInformation(),
+                        new AxEvents(), new AxContextAlbums(), new AxTasks(), new AxPolicies()));
+
+        final AxArtifactKey modelKey = new AxArtifactKey("ModelKey", "0.0.1");
+        final AxArtifactKey schemasKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxArtifactKey eventsKey = new AxArtifactKey("EventsKey", "0.0.1");
+        final AxArtifactKey keyInfoKey = new AxArtifactKey("SchemasKey", "0.0.1");
+        final AxArtifactKey albumsKey = new AxArtifactKey("AlbumsKey", "0.0.1");
+        final AxArtifactKey tasksKey = new AxArtifactKey("TasksKey", "0.0.1");
+        final AxArtifactKey policiesKey = new AxArtifactKey("PoliciesKey", "0.0.1");
+
+        AxPolicyModel model = new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey));
+
+        model.register();
+
+        assertNotNull(model.getContextModel());
+        assertEquals("ModelKey:0.0.1", model.getKeys().get(0).getId());
+
+        model.clean();
+        assertNotNull(model);
+        assertEquals("AxPolicyModel:(AxPolicyModel:(key=AxArtifactKey:(n", model.toString().substring(0, 50));
+
+        final AxPolicyModel clonedModel = new AxPolicyModel(model);
+
+        assertNotEquals(0, model.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(model, model); // NOSONAR
+        assertEquals(model, clonedModel);
+        assertNotEquals(model, (Object) "Hello");
+        assertNotEquals(model, new AxPolicyModel(new AxArtifactKey()));
+        assertNotEquals(model, new AxPolicyModel(AxArtifactKey.getNullKey(), new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey)));
+        assertNotEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(), new AxKeyInformation(keyInfoKey),
+                        new AxEvents(eventsKey), new AxContextAlbums(albumsKey), new AxTasks(tasksKey),
+                        new AxPolicies(policiesKey)));
+        assertNotEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey), new AxKeyInformation(),
+                        new AxEvents(eventsKey), new AxContextAlbums(albumsKey), new AxTasks(tasksKey),
+                        new AxPolicies(policiesKey)));
+        assertNotEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey)));
+        assertNotEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey)));
+        assertNotEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(), new AxPolicies(policiesKey)));
+        assertNotEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies()));
+        assertEquals(model, new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey)));
+
+        assertEquals(0, model.compareTo(model));
+        assertEquals(0, model.compareTo(clonedModel));
+        assertNotEquals(0, model.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, model.compareTo(new AxPolicyModel(AxArtifactKey.getNullKey(),
+                        new AxContextSchemas(schemasKey), new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey),
+                        new AxContextAlbums(albumsKey), new AxTasks(tasksKey), new AxPolicies(policiesKey))));
+        assertNotEquals(0, model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey))));
+        assertNotEquals(0,
+                        model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                                        new AxKeyInformation(), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                                        new AxTasks(tasksKey), new AxPolicies(policiesKey))));
+        assertNotEquals(0, model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey))));
+        assertNotEquals(0,
+                        model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey),
+                                        new AxContextAlbums(), new AxTasks(tasksKey), new AxPolicies(policiesKey))));
+        assertNotEquals(0,
+                        model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey),
+                                        new AxContextAlbums(albumsKey), new AxTasks(), new AxPolicies(policiesKey))));
+        assertNotEquals(0,
+                        model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey),
+                                        new AxContextAlbums(albumsKey), new AxTasks(tasksKey), new AxPolicies())));
+        assertEquals(0, model.compareTo(new AxPolicyModel(modelKey, new AxContextSchemas(schemasKey),
+                        new AxKeyInformation(keyInfoKey), new AxEvents(eventsKey), new AxContextAlbums(albumsKey),
+                        new AxTasks(tasksKey), new AxPolicies(policiesKey))));
+
+        model = new SupportApexPolicyModelCreator().getModel();
+
+        AxValidationResult result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxArtifactKey savedPolicyKey = model.getKey();
+        model.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.setKey(savedPolicyKey);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxField badField = new AxField(new AxReferenceKey(model.getEvents().get("inEvent").getKey(), "BadField"),
+                        new AxArtifactKey("NonExistantSchema", "0.0.1"));
+        model.getEvents().get("inEvent").getParameterMap().put(badField.getKey().getLocalName(), badField);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getEvents().get("inEvent").getParameterMap().remove(badField.getKey().getLocalName());
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxContextAlbum badAlbum = new AxContextAlbum(new AxArtifactKey("BadAlbum", "0.0.1"), "SomeScope", true,
+                        new AxArtifactKey("NonExistantSchema", "0.0.1"));
+        model.getAlbums().getAlbumsMap().put(badAlbum.getKey(), badAlbum);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getAlbums().getAlbumsMap().remove(badAlbum.getKey());
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        model.getTasks().get("task").getContextAlbumReferences()
+                        .add(new AxArtifactKey("NonExistantContextAlbum", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getTasks().get("task").getContextAlbumReferences()
+                        .remove(new AxArtifactKey("NonExistantContextAlbum", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").getContextAlbumReferences()
+                        .add(new AxArtifactKey("NonExistantContextAlbum", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").getContextAlbumReferences()
+                        .remove(new AxArtifactKey("NonExistantContextAlbum", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxArtifactKey savedTrigger = model.getPolicies().get("policy").getStateMap().get("state").getTrigger();
+        model.getPolicies().get("policy").getStateMap().get("state")
+                        .setTrigger(new AxArtifactKey("NonExistantEvent", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").setTrigger(savedTrigger);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxArtifactKey savedDefaultTask = model.getPolicies().get("policy").getStateMap().get("state")
+                        .getDefaultTask();
+        model.getPolicies().get("policy").getStateMap().get("state")
+                        .setDefaultTask(new AxArtifactKey("NonExistantTask", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").setDefaultTask(savedDefaultTask);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // It is OK not to have TSL
+        final AxTaskSelectionLogic savedTaskSelectionLogic = model.getPolicies().get("policy").getStateMap()
+                        .get("state").getTaskSelectionLogic();
+        model.getPolicies().get("policy").getStateMap().get("state")
+                        .setTaskSelectionLogic(new AxTaskSelectionLogic(AxReferenceKey.getNullKey()));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").setTaskSelectionLogic(savedTaskSelectionLogic);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxStateOutput badStateOutput = new AxStateOutput(
+                        new AxReferenceKey(model.getPolicies().get("policy").getStateMap().get("state").getKey(),
+                                        "BadSO"),
+                        new AxArtifactKey("NonExistantEvent", "0.0.1"), AxReferenceKey.getNullKey());
+        model.getPolicies().get("policy").getStateMap().get("state").getStateOutputs()
+                        .put(badStateOutput.getKey().getLocalName(), badStateOutput);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").getStateOutputs()
+                        .remove(badStateOutput.getKey().getLocalName());
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxStateTaskReference badTaskReference = new AxStateTaskReference(
+                        new AxReferenceKey(model.getPolicies().get("policy").getStateMap().get("state").getKey(),
+                                        "NonExistantTask"),
+                        AxStateTaskOutputType.LOGIC, badStateOutput.getKey());
+        model.getPolicies().get("policy").getStateMap().get("state").getTaskReferences()
+                        .put(new AxArtifactKey("NonExistantTask", "0.0.1"), badTaskReference);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        badTaskReference.setStateTaskOutputType(AxStateTaskOutputType.DIRECT);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        model.getPolicies().get("policy").getStateMap().get("state").getTaskReferences()
+                        .remove(new AxArtifactKey("NonExistantTask", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxStateTaskReference tr = model.getPolicies().get("policy").getStateMap().get("state").getTaskReferences()
+                        .get(new AxArtifactKey("task", "0.0.1"));
+
+        final String savedStateOutputName = tr.getOutput().getLocalName();
+        tr.getOutput().setLocalName("NonExistantOutput");
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        tr.getOutput().setLocalName(savedStateOutputName);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        final AxStateOutput so = model.getPolicies().get("policy").getStateMap().get("state").getStateOutputs()
+                        .get(savedStateOutputName);
+
+        final AxArtifactKey savedOutEvent = so.getOutgoingEvent();
+        so.setOutgoingEvent(new AxArtifactKey("NonExistantEvent", "0.0.1"));
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        so.setOutgoingEvent(savedOutEvent);
+        result = new AxValidationResult();
+        result = model.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateOutputTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateOutputTest.java
new file mode 100644
index 000000000..049783a7f
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateOutputTest.java
@@ -0,0 +1,124 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test state outputs.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class StateOutputTest {
+
+    @Test
+    public void testStateOutput() {
+        assertNotNull(new AxStateOutput());
+        assertNotNull(new AxStateOutput(new AxReferenceKey()));
+        assertNotNull(new AxStateOutput(new AxReferenceKey(), new AxReferenceKey(), new AxArtifactKey()));
+        assertNotNull(new AxStateOutput(new AxReferenceKey(), new AxArtifactKey(), new AxReferenceKey()));
+
+        final AxStateOutput so = new AxStateOutput();
+
+        final AxReferenceKey soKey = new AxReferenceKey("SOStateParent", "0.0.1", "SOState", "SOName");
+        final AxReferenceKey nsKey = new AxReferenceKey("SOStateParent", "0.0.1", "NotUsed", "NextStateName");
+        final AxArtifactKey eKey = new AxArtifactKey("EventName", "0.0.1");
+
+        assertThatThrownBy(() -> so.setKey(null))
+            .hasMessage("key is marked non-null but is null");
+        so.setKey(soKey);
+        assertEquals("SOStateParent:0.0.1:SOState:SOName", so.getKey().getId());
+        assertEquals("SOStateParent:0.0.1:SOState:SOName", so.getKeys().get(0).getId());
+
+        assertThatThrownBy(() -> so.setNextState(null))
+            .hasMessage("nextState is marked non-null but is null");
+        so.setNextState(nsKey);
+        assertEquals(nsKey, so.getNextState());
+
+        assertThatThrownBy(() -> so.setOutgoingEvent(null))
+            .hasMessage("outgoingEvent is marked non-null but is null");
+        so.setOutgoingEvent(eKey);
+        assertEquals(eKey, so.getOutgoingEvent());
+
+        AxValidationResult result = new AxValidationResult();
+        result = so.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        so.setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = so.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        so.setKey(soKey);
+        result = new AxValidationResult();
+        result = so.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        so.setOutgoingEvent(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = so.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        so.setOutgoingEvent(eKey);
+        result = new AxValidationResult();
+        result = so.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        so.clean();
+
+        final AxStateOutput clonedPar = new AxStateOutput(so);
+        assertEquals("AxStateOutput:(stateKey=AxReferenceKey:(parentKeyN", clonedPar.toString().substring(0, 50));
+
+        assertNotEquals(0, so.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(so, so); // NOSONAR
+        assertEquals(so, clonedPar);
+        assertNotNull(so);
+        assertNotEquals(so, (Object) "Hello");
+        assertNotEquals(so, new AxStateOutput(AxReferenceKey.getNullKey(), eKey, nsKey));
+        assertNotEquals(so, new AxStateOutput(soKey, new AxArtifactKey(), nsKey));
+        assertNotEquals(so, new AxStateOutput(soKey, eKey, new AxReferenceKey()));
+        assertEquals(so, new AxStateOutput(soKey, eKey, nsKey));
+
+        assertEquals(0, so.compareTo(so));
+        assertEquals(0, so.compareTo(clonedPar));
+        assertNotEquals(0, so.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, so.compareTo(null));
+        assertNotEquals(0, so.compareTo(new AxStateOutput(AxReferenceKey.getNullKey(), eKey, nsKey)));
+        assertNotEquals(0, so.compareTo(new AxStateOutput(soKey, new AxArtifactKey(), nsKey)));
+        assertNotEquals(0, so.compareTo(new AxStateOutput(soKey, eKey, new AxReferenceKey())));
+        assertEquals(0, so.compareTo(new AxStateOutput(soKey, eKey, nsKey)));
+
+        assertNotNull(so.getKeys());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateTaskReferenceTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateTaskReferenceTest.java
new file mode 100644
index 000000000..568c47f61
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateTaskReferenceTest.java
@@ -0,0 +1,144 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test state task references.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class StateTaskReferenceTest {
+
+    @Test
+    public void testStateTaskReference() {
+        assertNotNull(new AxStateTaskReference());
+        assertNotNull(new AxStateTaskReference(new AxReferenceKey()));
+        assertNotNull(new AxStateTaskReference(new AxReferenceKey(), AxStateTaskOutputType.UNDEFINED,
+                        new AxReferenceKey()));
+        assertNotNull(new AxStateTaskReference(new AxReferenceKey(), new AxArtifactKey(),
+                        AxStateTaskOutputType.UNDEFINED, new AxReferenceKey()));
+
+        AxStateTaskReference stRef = new AxStateTaskReference();
+
+        AxReferenceKey stRefKey = new AxReferenceKey("StateParent", "0.0.1", "SOState", "SOName");
+
+        assertThatThrownBy(() -> stRef.setKey(null))
+            .hasMessage("key may not be null");
+        stRef.setKey(stRefKey);
+        assertEquals("StateParent:0.0.1:SOState:SOName", stRef.getKey().getId());
+        assertEquals("StateParent:0.0.1:SOState:SOName", stRef.getKeys().get(0).getId());
+
+        assertThatThrownBy(() -> stRef.setStateTaskOutputType(null))
+            .hasMessage("outputType may not be null");
+        stRef.setStateTaskOutputType(AxStateTaskOutputType.UNDEFINED);
+        assertEquals(AxStateTaskOutputType.UNDEFINED, stRef.getStateTaskOutputType());
+        stRef.setStateTaskOutputType(AxStateTaskOutputType.DIRECT);
+        assertEquals(AxStateTaskOutputType.DIRECT, stRef.getStateTaskOutputType());
+        stRef.setStateTaskOutputType(AxStateTaskOutputType.LOGIC);
+        assertEquals(AxStateTaskOutputType.LOGIC, stRef.getStateTaskOutputType());
+
+        assertThatThrownBy(() -> stRef.setOutput(null))
+            .hasMessage("output may not be null");
+        AxReferenceKey soKey = new AxReferenceKey("StateParent", "0.0.1", "SOState", "STRef0");
+        stRef.setOutput(soKey);
+        assertEquals(soKey, stRef.getOutput());
+
+        AxValidationResult result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        stRef.setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        stRef.setKey(stRefKey);
+        result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        stRef.setStateTaskOutputType(AxStateTaskOutputType.UNDEFINED);
+        result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        stRef.setStateTaskOutputType(AxStateTaskOutputType.LOGIC);
+        result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        stRef.setOutput(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        stRef.setOutput(soKey);
+        result = new AxValidationResult();
+        result = stRef.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        stRef.clean();
+
+        AxStateTaskReference clonedStRef = new AxStateTaskReference(stRef);
+        assertEquals("AxStateTaskReference:(stateKey=AxReferenceKey:(par", clonedStRef.toString().substring(0, 50));
+
+        assertNotEquals(0, stRef.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(stRef, stRef); // NOSONAR
+        assertEquals(stRef, clonedStRef);
+        assertNotNull(stRef);
+        assertNotEquals(stRef, (Object) "Hello");
+        assertNotEquals(stRef, new AxStateTaskReference(AxReferenceKey.getNullKey(), AxStateTaskOutputType.LOGIC,
+                        soKey));
+        assertNotEquals(stRef, new AxStateTaskReference(stRefKey, AxStateTaskOutputType.DIRECT, soKey));
+        assertNotEquals(stRef, new AxStateTaskReference(stRefKey, AxStateTaskOutputType.LOGIC, new AxReferenceKey()));
+        assertEquals(stRef, new AxStateTaskReference(stRefKey, AxStateTaskOutputType.LOGIC, soKey));
+
+        assertNotNull(new AxStateTaskReference(new AxReferenceKey(), new AxArtifactKey(),
+                        AxStateTaskOutputType.UNDEFINED, new AxReferenceKey()));
+
+        assertEquals(0, stRef.compareTo(stRef));
+        assertEquals(0, stRef.compareTo(clonedStRef));
+        assertNotEquals(0, stRef.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, stRef.compareTo(null));
+        assertNotEquals(0, stRef.compareTo(
+                        new AxStateTaskReference(AxReferenceKey.getNullKey(), AxStateTaskOutputType.LOGIC, soKey)));
+        assertNotEquals(0, stRef.compareTo(new AxStateTaskReference(stRefKey, AxStateTaskOutputType.DIRECT, soKey)));
+        assertNotEquals(0, stRef.compareTo(
+                        new AxStateTaskReference(stRefKey, AxStateTaskOutputType.LOGIC, new AxReferenceKey())));
+        assertEquals(0, stRef.compareTo(new AxStateTaskReference(stRefKey, AxStateTaskOutputType.LOGIC, soKey)));
+
+        assertNotNull(stRef.getKeys());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateTest.java
new file mode 100644
index 000000000..7fbe78078
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/StateTest.java
@@ -0,0 +1,461 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test policy states.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class StateTest {
+
+    @Test
+    public void testState() {
+        final TreeMap<String, AxStateOutput> soEmptyMap = new TreeMap<>();
+        final TreeSet<AxArtifactKey> ctxtEmptySet = new TreeSet<>();
+        final TreeMap<String, AxStateFinalizerLogic> sflEmptyMap = new TreeMap<>();
+        final TreeMap<AxArtifactKey, AxStateTaskReference> trEmptyMap = new TreeMap<>();
+
+        final TreeMap<String, AxStateOutput> soMap = new TreeMap<>();
+        final TreeSet<AxArtifactKey> ctxtSet = new TreeSet<>();
+        final TreeMap<String, AxStateFinalizerLogic> sflMap = new TreeMap<>();
+        final TreeMap<AxArtifactKey, AxStateTaskReference> trMap = new TreeMap<>();
+
+        assertNotNull(new AxState());
+        assertNotNull(new AxState(new AxReferenceKey()));
+        assertNotNull(new AxState(new AxStateParamsBuilder().key(new AxReferenceKey()).trigger(new AxArtifactKey())
+                        .stateOutputs(soEmptyMap).contextAlbumReferenceSet(ctxtEmptySet)
+                        .taskSelectionLogic(new AxTaskSelectionLogic()).stateFinalizerLogicMap(sflEmptyMap)
+                        .defaultTask(new AxArtifactKey()).taskReferenceMap(trEmptyMap)));
+
+        final AxState state = new AxState();
+
+        final AxReferenceKey stateKey = new AxReferenceKey("PolicyName", "0.0.1", "StateName");
+        final AxReferenceKey stateKeyNext = new AxReferenceKey("PolicyName", "0.0.1", "StateNameNext");
+        final AxReferenceKey stateKeyBad = new AxReferenceKey("PolicyName", "0.0.1", "BadStateName");
+        final AxArtifactKey triggerKey = new AxArtifactKey("TriggerName", "0.0.1");
+        final AxTaskSelectionLogic tsl = new AxTaskSelectionLogic(stateKey, "TSL", "LogicFlavour", "Some Logic");
+        final AxArtifactKey defTaskKey = new AxArtifactKey("TaskName", "0.0.1");
+        final AxArtifactKey taskKey1 = new AxArtifactKey("Task1", "0.0.1");
+        final AxArtifactKey taskKey2 = new AxArtifactKey("Task2", "0.0.1");
+        final AxArtifactKey taskKeyBad = new AxArtifactKey("TaskBad", "0.0.1");
+
+        assertThatThrownBy(() -> state.setKey(null))
+            .hasMessage("key may not be null");
+        state.setKey(stateKey);
+        assertEquals("PolicyName:0.0.1:NULL:StateName", state.getKey().getId());
+        assertEquals("PolicyName:0.0.1:NULL:StateName", state.getKeys().get(0).getId());
+
+        final AxStateOutput so0 = new AxStateOutput(new AxReferenceKey(stateKey, "SO0"), triggerKey,
+                        new AxReferenceKey());
+        final AxStateOutput soU = new AxStateOutput(new AxReferenceKey(stateKey, "SOU"), triggerKey, stateKeyNext);
+        final AxStateOutput soSame = new AxStateOutput(new AxReferenceKey(stateKey, "SOU"), triggerKey, stateKey);
+        final AxArtifactKey cr0 = new AxArtifactKey("ContextReference", "0.0.1");
+        final AxStateFinalizerLogic sfl = new AxStateFinalizerLogic(stateKey, "SFLogicName", "LogicFlavour", "Logic");
+        final AxStateFinalizerLogic sflU = new AxStateFinalizerLogic(stateKey, "UnusedSFLogicName", "LogicFlavour",
+                        "Logic");
+        final AxStateTaskReference str0 = new AxStateTaskReference(new AxReferenceKey(stateKey, "STR0"),
+                        AxStateTaskOutputType.DIRECT, so0.getKey());
+        final AxStateTaskReference str1 = new AxStateTaskReference(new AxReferenceKey(stateKey, "STR1"),
+                        AxStateTaskOutputType.DIRECT, so0.getKey());
+        final AxStateTaskReference str2 = new AxStateTaskReference(new AxReferenceKey(stateKey, "STR2"),
+                        AxStateTaskOutputType.LOGIC, sfl.getKey());
+
+        final AxStateTaskReference strBadState = new AxStateTaskReference(new AxReferenceKey(stateKeyBad, "STR2"),
+                        AxStateTaskOutputType.LOGIC, sfl.getKey());
+        final AxStateTaskReference strBadStateOutput = new AxStateTaskReference(new AxReferenceKey(stateKey, "STR2"),
+                        AxStateTaskOutputType.UNDEFINED, sfl.getKey());
+        final AxStateTaskReference strBadStateFinalizerLogic = new AxStateTaskReference(
+                        new AxReferenceKey(stateKeyBad, "STR2"), AxStateTaskOutputType.LOGIC,
+                        new AxReferenceKey(stateKey, "SomeSFL"));
+
+        soMap.put(so0.getKey().getLocalName(), so0);
+        ctxtSet.add(cr0);
+        sflMap.put(sfl.getKey().getLocalName(), sfl);
+        trMap.put(defTaskKey.getKey(), str0);
+        trMap.put(taskKey1.getKey(), str1);
+        trMap.put(taskKey2.getKey(), str2);
+
+        assertThatThrownBy(() -> state.setTrigger(null))
+            .hasMessage("trigger may not be null");
+        state.setTrigger(triggerKey);
+        assertEquals(triggerKey, state.getTrigger());
+
+        assertThatThrownBy(() -> state.setStateOutputs(null))
+            .hasMessage("stateOutputs may not be null");
+        state.setStateOutputs(soMap);
+        assertEquals(soMap, state.getStateOutputs());
+
+        assertThatThrownBy(() -> state.setContextAlbumReferences(null))
+            .hasMessage("contextAlbumReferenceSet may not be null");
+        state.setContextAlbumReferences(ctxtSet);
+        assertEquals(ctxtSet, state.getContextAlbumReferences());
+
+        assertThatThrownBy(() -> state.setTaskSelectionLogic(null))
+            .hasMessage("taskSelectionLogic may not be null");
+        assertEquals(false, state.checkSetTaskSelectionLogic());
+        state.setTaskSelectionLogic(tsl);
+        assertEquals(tsl, state.getTaskSelectionLogic());
+        assertEquals(true, state.checkSetTaskSelectionLogic());
+
+        assertThatThrownBy(() -> state.setStateFinalizerLogicMap(null))
+            .hasMessage("stateFinalizerLogic may not be null");
+        state.setStateFinalizerLogicMap(sflMap);
+        assertEquals(sflMap, state.getStateFinalizerLogicMap());
+
+        assertThatThrownBy(() -> state.setDefaultTask(null))
+            .hasMessage("defaultTask may not be null");
+        state.setDefaultTask(defTaskKey);
+        assertEquals(defTaskKey, state.getDefaultTask());
+
+        assertThatThrownBy(() -> state.setTaskReferences(null))
+            .hasMessage("taskReferenceMap may not be null");
+        state.setTaskReferences(trMap);
+        assertEquals(trMap, state.getTaskReferences());
+
+        state.buildReferences();
+        assertEquals(state.getKey(), state.getKeys().get(0));
+        state.getTaskSelectionLogic().getKey().setLocalName(AxKey.NULL_KEY_NAME);
+        state.buildReferences();
+        assertEquals(state.getKey(), state.getKeys().get(0));
+
+        final Set<String> stateSet = state.getNextStateSet();
+        assertEquals(1, stateSet.size());
+
+        AxValidationResult result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        state.setKey(stateKey);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setTrigger(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        state.setTrigger(triggerKey);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setStateOutputs(soEmptyMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        state.setStateOutputs(soMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        so0.getKey().setParentLocalName("Zooby");
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        so0.getKey().setParentLocalName("StateName");
+        state.setStateOutputs(soMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        soMap.put("NullOutput", null);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        soMap.remove("NullOutput");
+        state.setStateOutputs(soMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        soMap.put("DupOutput", so0);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        soMap.remove("DupOutput");
+        state.setStateOutputs(soMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        soMap.put("UnusedOutput", soU);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.OBSERVATION, result.getValidationResult());
+
+        soMap.remove("UnusedOutput");
+        state.setStateOutputs(soMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        soMap.put("OutputToSameState", soSame);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        soMap.remove("OutputToSameState");
+        state.setStateOutputs(soMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Empty context reference set is OK
+        state.setContextAlbumReferences(ctxtEmptySet);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setContextAlbumReferences(ctxtSet);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        ctxtSet.add(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        ctxtSet.remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Null TSL is OK
+        state.getTaskSelectionLogic().setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.getTaskSelectionLogic().setKey(new AxReferenceKey(stateKey, "TSL"));
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setDefaultTask(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        state.setDefaultTask(defTaskKey);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setTaskReferences(trEmptyMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        state.setTaskReferences(trMap);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        trMap.put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        trMap.remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        trMap.put(AxArtifactKey.getNullKey(), str0);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        trMap.remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        trMap.put(taskKeyBad, strBadStateOutput);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        trMap.remove(taskKeyBad);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        trMap.put(taskKeyBad, strBadState);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        trMap.remove(taskKeyBad);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        trMap.put(taskKeyBad, strBadStateFinalizerLogic);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        trMap.remove(taskKeyBad);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.setDefaultTask(new AxArtifactKey("NonExistantTask", "0.0.1"));
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        state.setDefaultTask(defTaskKey);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        sflMap.put("NullSFL", null);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        sflMap.remove("NullSFL");
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        sflMap.put(sflU.getKey().getLocalName(), sflU);
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.OBSERVATION, result.getValidationResult());
+
+        sflMap.remove(sflU.getKey().getLocalName());
+        result = new AxValidationResult();
+        result = state.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        state.clean();
+
+        final AxState clonedState = new AxState(state);
+        assertEquals("AxState:(stateKey=AxReferenceKey:(parent", clonedState.toString().substring(0, 40));
+
+        assertNotEquals(0, state.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(state, state); // NOSONAR
+        assertEquals(state, clonedState);
+        assertNotNull(state);
+
+        Object helloObj = "Hello";
+        assertNotEquals(state, helloObj);
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(new AxReferenceKey()).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(new AxArtifactKey())
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soEmptyMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtEmptySet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet)
+                        .taskSelectionLogic(new AxTaskSelectionLogic()).stateFinalizerLogicMap(sflMap)
+                        .defaultTask(defTaskKey).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflEmptyMap).defaultTask(defTaskKey).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(new AxArtifactKey()).taskReferenceMap(trMap)));
+        assertNotEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trEmptyMap)));
+        assertEquals(state, new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                     .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                     .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap)));
+
+        assertEquals(0, state.compareTo(state));
+        assertEquals(0, state.compareTo(clonedState));
+        assertNotEquals(0, state.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, state.compareTo(null));
+        assertNotEquals(0,
+                        state.compareTo(new AxState(new AxStateParamsBuilder().key(new AxReferenceKey())
+                                        .trigger(triggerKey).stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet)
+                                        .taskSelectionLogic(tsl).stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey)
+                                        .taskReferenceMap(trMap))));
+        assertNotEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey)
+                        .trigger(new AxArtifactKey()).stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet)
+                        .taskSelectionLogic(tsl).stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey)
+                        .taskReferenceMap(trMap))));
+        assertNotEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soEmptyMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap))));
+        assertNotEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtEmptySet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap))));
+        assertNotEquals(0,
+                        state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet)
+                                        .taskSelectionLogic(new AxTaskSelectionLogic()).stateFinalizerLogicMap(sflMap)
+                                        .defaultTask(defTaskKey).taskReferenceMap(trMap))));
+        assertNotEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflEmptyMap).defaultTask(defTaskKey).taskReferenceMap(trMap))));
+        assertNotEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(new AxArtifactKey()).taskReferenceMap(trMap))));
+        assertNotEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trEmptyMap))));
+        assertEquals(0, state.compareTo(new AxState(new AxStateParamsBuilder().key(stateKey).trigger(triggerKey)
+                        .stateOutputs(soMap).contextAlbumReferenceSet(ctxtSet).taskSelectionLogic(tsl)
+                        .stateFinalizerLogicMap(sflMap).defaultTask(defTaskKey).taskReferenceMap(trMap))));
+
+        assertNotNull(state.getKeys());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/TaskParameterTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/TaskParameterTest.java
new file mode 100644
index 000000000..4255b495d
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/TaskParameterTest.java
@@ -0,0 +1,110 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+
+/**
+ * Test task parameters.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class TaskParameterTest {
+
+    @Test
+    public void testTaskParameter() {
+        assertNotNull(new AxTaskParameter());
+        assertNotNull(new AxTaskParameter(new AxReferenceKey()));
+        assertNotNull(new AxTaskParameter(new AxReferenceKey(), "DefaultValue"));
+
+        final AxTaskParameter par = new AxTaskParameter();
+
+        final AxReferenceKey parKey = new AxReferenceKey("ParParentName", "0.0.1", "PLN", "LN");
+        par.setKey(parKey);
+        assertEquals("ParParentName:0.0.1:PLN:LN", par.getKey().getId());
+        assertEquals("ParParentName:0.0.1:PLN:LN", par.getKeys().get(0).getId());
+
+        par.setDefaultValue("DefaultValue");
+        assertEquals("DefaultValue", par.getTaskParameterValue());
+
+        AxValidationResult result = new AxValidationResult();
+        result = par.validate(result);
+        assertEquals(AxValidationResult.ValidationResult.VALID, result.getValidationResult());
+
+        par.setKey(AxReferenceKey.getNullKey());
+        result = new AxValidationResult();
+        result = par.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        par.setKey(parKey);
+        result = new AxValidationResult();
+        result = par.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        assertThatThrownBy(() -> par.setDefaultValue(null))
+            .hasMessage("defaultValue may not be null");
+        par.setDefaultValue("");
+        result = new AxValidationResult();
+        result = par.validate(result);
+        assertEquals(ValidationResult.WARNING, result.getValidationResult());
+
+        par.setDefaultValue("DefaultValue");
+        result = new AxValidationResult();
+        result = par.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        par.clean();
+
+        final AxTaskParameter clonedPar = new AxTaskParameter(par);
+        assertEquals("AxTaskParameter:(key=AxReferenceKey:(parentKeyName=ParParentName,parentKeyVersion=0.0.1,"
+                        + "parentLocalName=PLN,localName=LN),defaultValue=DefaultValue)", clonedPar.toString());
+
+        assertNotEquals(0, par.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(par, par); // NOSONAR
+        assertEquals(par, clonedPar);
+        assertNotNull(par);
+        assertNotEquals(par, (Object) "Hello");
+        assertNotEquals(par, new AxTaskParameter(AxReferenceKey.getNullKey(), "DefaultValue"));
+        assertNotEquals(par, new AxTaskParameter(parKey, "OtherDefaultValue"));
+        assertEquals(par, new AxTaskParameter(parKey, "DefaultValue"));
+
+        assertEquals(0, par.compareTo(par));
+        assertEquals(0, par.compareTo(clonedPar));
+        assertNotEquals(0, par.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, par.compareTo(null));
+        assertNotEquals(0, par.compareTo(new AxTaskParameter(AxReferenceKey.getNullKey(), "DefaultValue")));
+        assertNotEquals(0, par.compareTo(new AxTaskParameter(parKey, "OtherDefaultValue")));
+        assertEquals(0, par.compareTo(new AxTaskParameter(parKey, "DefaultValue")));
+
+        assertNotNull(par.getKeys());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/TasksTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/TasksTest.java
new file mode 100644
index 000000000..9c7866c85
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/concepts/TasksTest.java
@@ -0,0 +1,259 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019-2020,2022 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.concepts;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult.ValidationResult;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+
+/**
+ * Test policy tasks.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class TasksTest {
+
+    @Test
+    public void testTasks() {
+        final TreeMap<String, AxTaskParameter> tpEmptyMap = new TreeMap<>();
+        final TreeSet<AxArtifactKey> ctxtEmptySet = new TreeSet<>();
+
+        final TreeMap<String, AxTaskParameter> tpMap = new TreeMap<>();
+        final TreeSet<AxArtifactKey> ctxtSet = new TreeSet<>();
+
+        assertNotNull(new AxTask());
+        assertNotNull(new AxTask(new AxArtifactKey()));
+        assertNotNull(new AxTask(new AxArtifactKey(), tpMap, ctxtSet, new AxTaskLogic()));
+
+        final AxTask task = new AxTask();
+
+        final AxArtifactKey taskKey = new AxArtifactKey("TaskName", "0.0.1");
+        task.setKey(taskKey);
+        assertEquals("TaskName:0.0.1", task.getKey().getId());
+        assertEquals("TaskName:0.0.1", task.getKeys().get(0).getId());
+
+        final AxTaskParameter tp0 = new AxTaskParameter(new AxReferenceKey(taskKey, "TP0"), "DefaultValue");
+        final AxArtifactKey cr0 = new AxArtifactKey("ContextReference", "0.0.1");
+        final AxTaskLogic tl = new AxTaskLogic(taskKey, "LogicName", "LogicFlavour", "Logic");
+
+        tpMap.put(tp0.getKey().getLocalName(), tp0);
+        ctxtSet.add(cr0);
+
+        task.setInputEvent(new AxEvent());
+        task.setOutputEvents(Map.of("Event", new AxEvent()));
+
+        task.setTaskParameters(tpMap);
+        assertEquals(tpMap, task.getTaskParameters());
+
+        task.setContextAlbumReferences(ctxtSet);
+        assertEquals(ctxtSet, task.getContextAlbumReferences());
+
+        task.setTaskLogic(tl);
+        assertEquals(tl, task.getTaskLogic());
+
+        task.setKey(taskKey);
+        assertEquals("TaskName:0.0.1", task.getKey().getId());
+        assertEquals("TaskName:0.0.1", task.getKeys().get(0).getId());
+
+        task.buildReferences();
+        assertEquals(1, task.getTaskParameters().size());
+
+        AxValidationResult result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        task.setKey(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        task.setKey(taskKey);
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Empty task parameter map is OK
+        task.setTaskParameters(tpEmptyMap);
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        task.setTaskParameters(tpMap);
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        tpMap.put("NullField", null);
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        tpMap.remove("NullField");
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        // Empty context reference set is OK
+        task.setContextAlbumReferences(ctxtEmptySet);
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        task.setContextAlbumReferences(ctxtSet);
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        ctxtSet.add(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        ctxtSet.remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = task.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        task.clean();
+
+        final AxTask clonedTask = new AxTask(task);
+        assertEquals("AxTask:(key=AxArtifactKey:(name=TaskName", clonedTask.toString().substring(0, 40));
+
+        assertNotEquals(0, task.hashCode());
+        // disabling sonar because this code tests the equals() method
+        assertEquals(task, task); // NOSONAR
+        assertEquals(task, clonedTask);
+        assertNotNull(task);
+
+        Object helloObj = "Hello";
+        assertNotEquals(task, helloObj);
+        assertNotEquals(task, new AxTask(new AxArtifactKey(), tpMap, ctxtSet, tl));
+        assertEquals(task, new AxTask(taskKey, tpMap, ctxtSet, tl));
+        assertNotEquals(task, new AxTask(taskKey, tpEmptyMap, ctxtSet, tl));
+        assertNotEquals(task, new AxTask(taskKey, tpMap, ctxtEmptySet, tl));
+        assertNotEquals(task, new AxTask(taskKey, tpMap, ctxtSet, new AxTaskLogic()));
+        assertEquals(task, new AxTask(taskKey, tpMap, ctxtSet, tl));
+
+        assertEquals(0, task.compareTo(task));
+        assertEquals(0, task.compareTo(clonedTask));
+        assertNotEquals(0, task.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, task.compareTo(null));
+        assertNotEquals(0, task.compareTo(new AxTask(new AxArtifactKey(), tpMap, ctxtSet, tl)));
+        assertEquals(0, task.compareTo(new AxTask(taskKey, tpMap, ctxtSet, tl)));
+        assertNotEquals(0, task.compareTo(new AxTask(taskKey, tpEmptyMap, ctxtSet, tl)));
+        assertNotEquals(0, task.compareTo(new AxTask(taskKey, tpMap, ctxtEmptySet, tl)));
+        assertNotEquals(0, task.compareTo(new AxTask(taskKey, tpMap, ctxtSet, new AxTaskLogic())));
+        assertEquals(0, task.compareTo(new AxTask(taskKey, tpMap, ctxtSet, tl)));
+
+        assertNotNull(task.getKeys());
+
+        final AxTasks tasks = new AxTasks();
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        // Invalid, no tasks in task map
+        tasks.setKey(new AxArtifactKey("TasksKey", "0.0.1"));
+        assertEquals("TasksKey:0.0.1", tasks.getKey().getId());
+
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        tasks.getTaskMap().put(taskKey, task);
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        tasks.getTaskMap().put(AxArtifactKey.getNullKey(), null);
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        tasks.getTaskMap().remove(AxArtifactKey.getNullKey());
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        tasks.getTaskMap().put(new AxArtifactKey("NullValueKey", "0.0.1"), null);
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        tasks.getTaskMap().remove(new AxArtifactKey("NullValueKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        tasks.getTaskMap().put(new AxArtifactKey("BadTaskKey", "0.0.1"), task);
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.INVALID, result.getValidationResult());
+
+        tasks.getTaskMap().remove(new AxArtifactKey("BadTaskKey", "0.0.1"));
+        result = new AxValidationResult();
+        result = tasks.validate(result);
+        assertEquals(ValidationResult.VALID, result.getValidationResult());
+
+        tasks.clean();
+
+        final AxTasks clonedTasks = new AxTasks(tasks);
+        assertEquals("AxTasks:(key=AxArtifactKey:(name=TasksKey,version=0.0.1),tas",
+                        clonedTasks.toString().substring(0, 60));
+
+        assertNotEquals(0, tasks.hashCode());
+
+        // disabling sonar because this code tests the equals() method
+        assertEquals(tasks, tasks); // NOSONAR
+        assertEquals(tasks, clonedTasks);
+        assertNotNull(tasks);
+        assertNotEquals(tasks, helloObj);
+        assertNotEquals(tasks, new AxTasks(new AxArtifactKey()));
+
+        assertEquals(0, tasks.compareTo(tasks));
+        assertEquals(0, tasks.compareTo(clonedTasks));
+        assertNotEquals(0, tasks.compareTo(null));
+        assertNotEquals(0, tasks.compareTo(new AxArtifactKey()));
+        assertNotEquals(0, tasks.compareTo(new AxTasks(new AxArtifactKey())));
+
+        clonedTasks.get(taskKey).getTaskLogic().setLogic("SomeChangedLogic");
+        assertNotEquals(0, tasks.compareTo(clonedTasks));
+
+        assertEquals(tasks.getKey(), tasks.getKeys().get(0));
+
+        assertEquals("TaskName", tasks.get("TaskName").getKey().getName());
+        assertEquals("TaskName", tasks.get("TaskName", "0.0.1").getKey().getName());
+        assertEquals(1, tasks.getAll("TaskName", "0.0.1").size());
+        assertEquals(0, tasks.getAll("NonExistantTaskName").size());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/ApexPolicyModelTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/ApexPolicyModelTest.java
new file mode 100644
index 000000000..48e4f87f9
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/ApexPolicyModelTest.java
@@ -0,0 +1,138 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+
+public class ApexPolicyModelTest {
+    private static final String VALID_MODEL_STRING = "***validation of model successful***";
+
+    private static final String OBSERVATION_MODEL_STRING = "\n"
+                    + "***observations noted during validation of model***\n"
+                    + "AxReferenceKey:(parentKeyName=policy,parentKeyVersion=0.0.1,parentLocalName=NULL,"
+                    + "localName=state):org.onap.policy.apex.model.policymodel.concepts.AxState:OBSERVATION:"
+                    + "state output stateOutput0 is not used directly by any task\n"
+                    + "********************************";
+
+    private static final String WARNING_MODEL_STRING = "\n" + "***warnings issued during validation of model***\n"
+                    + "AxArtifactKey:(name=policy,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicy:WARNING:state AxReferenceKey:"
+                    + "(parentKeyName=policy,parentKeyVersion=0.0.1,parentLocalName=NULL,localName=anotherState) "
+                    + "is not referenced in the policy execution tree\n" + "********************************";
+
+    private static final String INVALID_MODEL_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=contextAlbum0,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum:INVALID:scope is not defined\n"
+                    + "AxArtifactKey:(name=contextAlbum1,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum:INVALID:scope is not defined\n"
+                    + "********************************";
+
+    private static final String INVALID_MODEL_MALSTRUCTURED_STRING = "\n" + "***validation of model failed***\n"
+                    + "AxArtifactKey:(name=policyModel_KeyInfo,version=0.0.1):"
+                    + "org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation:INVALID:"
+                    + "keyInfoMap may not be empty\n" + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel_KeyInfo,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel_Schemas,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel_Events,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel_Albums,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel_Tasks,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel:INVALID:"
+                    + "key information not found for key AxArtifactKey:(name=policyModel_Policies,version=0.0.1)\n"
+                    + "AxArtifactKey:(name=policyModel_Schemas,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas:INVALID:"
+                    + "contextSchemas may not be empty\n" + "AxArtifactKey:(name=policyModel_Events,version=0.0.1):"
+                    + "org.onap.policy.apex.model.eventmodel.concepts.AxEvents:INVALID:eventMap may not be empty\n"
+                    + "AxArtifactKey:(name=policyModel_Albums,version=0.0.1):"
+                    + "org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums:OBSERVATION:albums are empty\n"
+                    + "AxArtifactKey:(name=policyModel_Tasks,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxTasks:INVALID:taskMap may not be empty\n"
+                    + "AxArtifactKey:(name=policyModel_Policies,version=0.0.1)"
+                    + ":org.onap.policy.apex.model.policymodel.concepts.AxPolicies:INVALID:policyMap may not be empty\n"
+                    + "********************************";
+
+    TestApexModel<AxPolicyModel> testApexModel;
+
+    /**
+     * Set up the policy model tests.
+     *
+     * @throws Exception on setup errors
+     */
+    @Before
+    public void setup() throws Exception {
+        testApexModel = new TestApexModel<AxPolicyModel>(AxPolicyModel.class, new SupportApexPolicyModelCreator());
+    }
+
+    @Test
+    public void testModelValid() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelValid();
+        assertEquals(VALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateObservation() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateObservation();
+        assertEquals(OBSERVATION_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testApexModelVaidateWarning() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateWarning();
+        assertEquals(WARNING_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateInvalidModel() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateInvalidModel();
+        assertEquals(INVALID_MODEL_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelVaidateMalstructured() throws Exception {
+        final AxValidationResult result = testApexModel.testApexModelVaidateMalstructured();
+        assertEquals(INVALID_MODEL_MALSTRUCTURED_STRING, result.toString());
+    }
+
+    @Test
+    public void testModelWriteReadJson() throws Exception {
+        testApexModel.testApexModelWriteReadJson();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyAnalyserTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyAnalyserTest.java
new file mode 100644
index 000000000..b1e2d5cbd
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyAnalyserTest.java
@@ -0,0 +1,60 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+
+public class PolicyAnalyserTest {
+    @Test
+    public void test() {
+        final AxPolicyModel apexModel = new SupportApexPolicyModelCreator().getModel();
+
+        final PolicyAnalyser policyAnalyser = new PolicyAnalyser();
+        final PolicyAnalysisResult analysisResult = policyAnalyser.analyse(apexModel);
+
+        assertEquals(EXPECTED_ANALYSIS_RESULT, analysisResult.toString());
+
+        assertNotNull(analysisResult.getUsedContextAlbums());
+        assertNotNull(analysisResult.getUsedContextSchemas());
+        assertNotNull(analysisResult.getUsedEvents());
+        assertNotNull(analysisResult.getUsedTasks());
+        assertNotNull(analysisResult.getUnusedContextAlbums());
+        assertNotNull(analysisResult.getUnusedContextSchemas());
+        assertNotNull(analysisResult.getUnusedEvents());
+        assertNotNull(analysisResult.getUnusedTasks());
+    }
+
+    private static final String EXPECTED_ANALYSIS_RESULT = "" + "Context Schema usage\n" + " MapType:0.0.1\n"
+            + "  contextAlbum0:0.0.1\n" + " StringType:0.0.1\n" + "  contextAlbum1:0.0.1\n"
+            + " eventContextItem0:0.0.1\n" + "  inEvent:0.0.1\n" + "  outEvent0:0.0.1\n" + "  outEvent1:0.0.1\n"
+            + " eventContextItem1:0.0.1\n" + "  inEvent:0.0.1\n" + "  outEvent0:0.0.1\n"
+            + "  outEvent1:0.0.1\n" + "Context Album usage\n" + " contextAlbum0:0.0.1\n"
+            + "  task:0.0.1\n" + "  policy:0.0.1:NULL:state\n" + " contextAlbum1:0.0.1\n" + "  task:0.0.1\n"
+            + "  policy:0.0.1:NULL:state\n" + "Event usage\n" + " inEvent:0.0.1\n" + "  policy:0.0.1:NULL:state\n"
+            + " outEvent0:0.0.1\n" + "  policy:0.0.1:NULL:state\n" + " outEvent1:0.0.1 (unused)\n" + "Task usage\n"
+            + " task:0.0.1\n" + "  policy:0.0.1:NULL:state\n";
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyLogicReaderTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyLogicReaderTest.java
new file mode 100644
index 000000000..a2cbe7415
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyLogicReaderTest.java
@@ -0,0 +1,84 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxLogic;
+
+/**
+ * Logic reader for policy tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class PolicyLogicReaderTest {
+
+    @Test
+    public void test() {
+        final AxReferenceKey logicKey = new AxReferenceKey("LogicParent", "0.0.1", "LogicInstanceName");
+
+        final PolicyLogicReader plReader = new PolicyLogicReader();
+
+        plReader.setLogicPackage("somewhere.over.the.rainbow");
+        assertEquals("somewhere.over.the.rainbow", plReader.getLogicPackage());
+
+        plReader.setDefaultLogic("FunkyDefaultLogic");
+        assertEquals("FunkyDefaultLogic", plReader.getDefaultLogic());
+
+        assertThatThrownBy(() -> new AxLogic(logicKey, "FunkyLogic", plReader))
+            .hasMessage("logic not found for logic "
+                            + "\"somewhere/over/the/rainbow/funkylogic/FunkyDefaultLogic.funkylogic\"");
+        plReader.setDefaultLogic(null);
+        assertThatThrownBy(() -> new AxLogic(logicKey, "FunkyLogic", plReader))
+            .hasMessage("logic not found for logic "
+                            + "\"somewhere/over/the/rainbow/funkylogic/LogicParentLogicInstanceName.funkylogic\"");
+        logicKey.setParentLocalName("LogicParentLocalName");
+        assertThatThrownBy(() -> new AxLogic(logicKey, "FunkyLogic", plReader))
+            .hasMessage("logic not found for logic " + "\"somewhere/over/the/rainbow/funkylogic/"
+                            + "LogicParentLogicParentLocalNameLogicInstanceName.funkylogic\"");
+        plReader.setLogicPackage("path.to.apex.logic");
+
+        AxLogic logic = new AxLogic(logicKey, "FunkyLogic", plReader);
+        assertThat(logic.getLogic()).endsWith("Way out man, this is funky logic!");
+
+        plReader.setLogicPackage("somewhere.over.the.rainbow");
+        plReader.setDefaultLogic("JavaLogic");
+
+        logic = new AxLogic(logicKey, "JAVA", plReader);
+        assertEquals("somewhere.over.the.rainbow.java.JavaLogic", logic.getLogic());
+
+        plReader.setDefaultLogic(null);
+
+        logic = new AxLogic(logicKey, "JAVA", plReader);
+        assertEquals("somewhere.over.the.rainbow.java.LogicParentLogicParentLocalNameLogicInstanceName",
+                        logic.getLogic());
+
+        logicKey.setParentLocalName(AxKey.NULL_KEY_NAME);
+        logic = new AxLogic(logicKey, "JAVA", plReader);
+        assertEquals("somewhere.over.the.rainbow.java.LogicParentLogicInstanceName", logic.getLogic());
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelComparerTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelComparerTest.java
new file mode 100644
index 000000000..691880d6b
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelComparerTest.java
@@ -0,0 +1,118 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020,2022 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.IOException;
+import java.util.UUID;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+public class PolicyModelComparerTest {
+
+    @Test
+    public void testPolicyComparer() throws IOException {
+        final AxPolicyModel leftApexModel = new SupportApexPolicyModelCreator().getModel();
+        final AxPolicyModel rightApexModel = new AxPolicyModel(leftApexModel);
+
+        PolicyModelComparer policyModelComparer = new PolicyModelComparer(leftApexModel, rightApexModel);
+
+        String resultString = policyModelComparer.asString(false, false);
+        String checkString = TextFileUtils
+            .getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonIdenticalVerboseValues.txt");
+        assertEquals(resultString.trim().replaceAll("\\s+", ""), checkString.trim().replaceAll("\\s+", ""));
+
+        resultString = policyModelComparer.asString(false, true);
+        checkString = TextFileUtils
+            .getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonIdenticalVerboseKeys.txt");
+        assertEquals(checkString.trim().replaceAll("\\s+", ""), resultString.trim().replaceAll("\\s+", ""));
+
+        resultString = policyModelComparer.asString(true, false);
+        checkString =
+            TextFileUtils.getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonIdenticalTerse.txt");
+        assertEquals(checkString.trim().replaceAll("\\s+", ""), resultString.trim().replaceAll("\\s+", ""));
+
+        resultString = policyModelComparer.asString(true, true);
+        checkString =
+            TextFileUtils.getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonIdenticalTerse.txt");
+        assertEquals(checkString.trim().replaceAll("\\s+", ""), resultString.trim().replaceAll("\\s+", ""));
+
+        final AxKeyInfo leftOnlyKeyInfo = new AxKeyInfo(new AxArtifactKey("LeftOnlyKeyInfo", "0.0.1"),
+            UUID.fromString("ce9168c-e6df-414f-9646-6da464b6f000"), "Left only key info");
+        final AxKeyInfo rightOnlyKeyInfo = new AxKeyInfo(new AxArtifactKey("RightOnlyKeyInfo", "0.0.1"),
+            UUID.fromString("ce9168c-e6df-414f-9646-6da464b6f001"), "Right only key info");
+
+        leftApexModel.getKeyInformation().getKeyInfoMap().put(leftOnlyKeyInfo.getKey(), leftOnlyKeyInfo);
+        rightApexModel.getKeyInformation().getKeyInfoMap().put(rightOnlyKeyInfo.getKey(), rightOnlyKeyInfo);
+
+        leftApexModel.getKeyInformation().getKeyInfoMap().get(new AxArtifactKey("inEvent", "0.0.1"))
+            .setDescription("Left InEvent Description");
+        rightApexModel.getKeyInformation().getKeyInfoMap().get(new AxArtifactKey("inEvent", "0.0.1"))
+            .setDescription("Right InEvent Description");
+
+        policyModelComparer = new PolicyModelComparer(leftApexModel, rightApexModel);
+
+        resultString = policyModelComparer.asString(false, false);
+        checkString = TextFileUtils
+            .getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonDifferentVerboseValues.txt");
+        assertEquals(resultString.trim().replaceAll("\\s+", ""), checkString.trim().replaceAll("\\s+", ""));
+
+        resultString = policyModelComparer.asString(false, true);
+        checkString = TextFileUtils
+            .getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonDifferentVerboseKeys.txt");
+        assertEquals(checkString.trim().replaceAll("\\s+", ""), resultString.trim().replaceAll("\\s+", ""));
+
+        resultString = policyModelComparer.asString(true, false);
+        checkString = TextFileUtils
+            .getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonDifferentTerseValues.txt");
+        assertEquals(checkString.trim().replaceAll("\\s+", ""), resultString.trim().replaceAll("\\s+", ""));
+
+        resultString = policyModelComparer.asString(true, true);
+        checkString = TextFileUtils
+            .getTextFileAsString("src/test/resources/checkFiles/PolicyModelComparisonDifferentTerseKeys.txt");
+        assertEquals(checkString.trim().replaceAll("\\s+", ""), resultString.trim().replaceAll("\\s+", ""));
+
+        assertNotNull(policyModelComparer.getContextAlbumComparisonResult());
+        assertNotNull(policyModelComparer.getContextAlbumKeyDifference());
+        assertNotNull(policyModelComparer.getContextSchemaComparisonResult());
+        assertNotNull(policyModelComparer.getContextSchemaKeyDifference());
+        assertNotNull(policyModelComparer.getEventComparisonResult());
+        assertNotNull(policyModelComparer.getEventKeyDifference());
+        assertNotNull(policyModelComparer.getKeyInfoComparisonResult());
+        assertNotNull(policyModelComparer.getKeyInformationKeyDifference());
+        assertNotNull(policyModelComparer.getPolicyComparisonResult());
+        assertNotNull(policyModelComparer.getPolicykeyDifference());
+        assertNotNull(policyModelComparer.getPolicyModelsKeyDifference());
+        assertNotNull(policyModelComparer.getTaskComparisonResult());
+        assertNotNull(policyModelComparer.getTaskKeyDifference());
+
+        assertNotNull(new PolicyComparer().compare(leftApexModel.getPolicies(), rightApexModel.getPolicies()));
+
+        assertEquals("****** policy map differences ******\n*** context s",
+            policyModelComparer.toString().substring(0, 50));
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelMergerTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelMergerTest.java
new file mode 100644
index 000000000..2bdf7499f
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelMergerTest.java
@@ -0,0 +1,92 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019 Nordix Foundation.
+ *  Modifications Copyright (C) 2020 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelException;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskLogic;
+
+/**
+ * Test model merging.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class PolicyModelMergerTest {
+
+    @Test
+    public void testPolicyModelMerger() throws ApexModelException {
+        final AxPolicyModel leftPolicyModel = new SupportApexPolicyModelCreator().getModel();
+        final AxPolicyModel rightPolicyModel = new SupportApexPolicyModelCreator().getModel();
+
+        AxPolicyModel mergedPolicyModel =
+            PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, false, false);
+        assertEquals(leftPolicyModel, mergedPolicyModel);
+        assertEquals(rightPolicyModel, mergedPolicyModel);
+
+        leftPolicyModel.setKey(new AxArtifactKey("LeftPolicyModel", "0.0.1"));
+        assertThatThrownBy(
+            () -> PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, false, false))
+                .hasMessageContaining("left model is invalid: \n***validation of model failed");
+
+        leftPolicyModel.setKey(new AxArtifactKey("LeftPolicyModel", "0.0.1"));
+        assertNotNull(PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, false, true, false));
+
+        leftPolicyModel.getKeyInformation().generateKeyInfo(leftPolicyModel);
+        mergedPolicyModel = PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, true, false);
+        assertNotNull(mergedPolicyModel);
+
+        rightPolicyModel.setKey(new AxArtifactKey("RightPolicyModel", "0.0.1"));
+        assertThatThrownBy(
+            () -> PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, false, false))
+                .hasMessageContaining("right model is invalid: \n***validation of model failed");
+
+        rightPolicyModel.setKey(new AxArtifactKey("RightPolicyModel", "0.0.1"));
+        assertNotNull(PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, false, true, false));
+
+        rightPolicyModel.getKeyInformation().generateKeyInfo(rightPolicyModel);
+        mergedPolicyModel = PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel, false, false);
+        assertNotNull(mergedPolicyModel);
+
+        final AxPolicyModel rightPolicyModel2 = new SupportApexPolicyModelCreator().getAnotherModel();
+        mergedPolicyModel = PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel2, true, false);
+        assertNotNull(mergedPolicyModel);
+
+        mergedPolicyModel = PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel2, true, true);
+        assertNotNull(mergedPolicyModel);
+
+        final AxPolicyModel rightPolicyModel3 = new SupportApexPolicyModelCreator().getModel();
+        AxArtifactKey taskArtifactKey = new AxArtifactKey("task", "0.0.1");
+        // fail when concepts in two policies have same name but different definition
+        // here make up some change so as to update the definition of the task in second policy
+        rightPolicyModel3.getTasks().getTaskMap().get(taskArtifactKey)
+            .setTaskLogic(new AxTaskLogic(taskArtifactKey, "logicName", "logicFlavour", "logicImpl"));
+        assertThatThrownBy(() -> PolicyModelMerger.getMergedPolicyModel(leftPolicyModel, rightPolicyModel3, true, true))
+            .hasMessage("\n Same task - task:0.0.1 with different definitions used in different policies");
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelSplitterTest.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelSplitterTest.java
new file mode 100644
index 000000000..902206d51
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/PolicyModelSplitterTest.java
@@ -0,0 +1,76 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.Set;
+import java.util.TreeSet;
+import org.junit.Test;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelException;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+
+public class PolicyModelSplitterTest {
+    @Test
+    public void test() throws ApexModelException {
+        final AxPolicyModel apexModel = new SupportApexPolicyModelCreator().getModel();
+
+        final Set<AxArtifactKey> requiredPolicySet = new TreeSet<AxArtifactKey>();
+        requiredPolicySet.add(new AxArtifactKey("policy", "0.0.1"));
+
+        // There's only one policy so a split of this model on that policy should return the same
+        // model
+        AxPolicyModel splitApexModel = null;
+        splitApexModel = PolicyModelSplitter.getSubPolicyModel(apexModel, requiredPolicySet);
+
+        // The only difference between the models should be that the unused event outEvent1 should
+        // not be in the split model
+        apexModel.getEvents().getEventMap().remove(new AxArtifactKey("outEvent1", "0.0.1"));
+        apexModel.getKeyInformation().getKeyInfoMap().remove(new AxArtifactKey("outEvent1", "0.0.1"));
+        assertEquals(apexModel, splitApexModel);
+
+        final Set<AxArtifactKey> requiredMissingPolicySet = new TreeSet<AxArtifactKey>();
+        requiredPolicySet.add(new AxArtifactKey("MissingPolicy", "0.0.1"));
+
+        AxPolicyModel missingSplitApexModel = null;
+        missingSplitApexModel = PolicyModelSplitter.getSubPolicyModel(apexModel, requiredMissingPolicySet);
+        assertNotNull(missingSplitApexModel);
+
+        splitApexModel = null;
+        splitApexModel = PolicyModelSplitter.getSubPolicyModel(apexModel, requiredPolicySet, true);
+
+        // The only difference between the models should be that the unused event outEvent1 should
+        // not be in the split model
+        apexModel.getEvents().getEventMap().remove(new AxArtifactKey("outEvent1", "0.0.1"));
+        apexModel.getKeyInformation().getKeyInfoMap().remove(new AxArtifactKey("outEvent1", "0.0.1"));
+        assertEquals(apexModel, splitApexModel);
+
+        // There's only one policy so a split of this model on that policy should return the same
+        // model
+        apexModel.getKey().setName("InvalidPolicyModelName");
+        assertThatThrownBy(() -> PolicyModelSplitter.getSubPolicyModel(apexModel, requiredPolicySet))
+            .hasMessageContaining("source model is invalid: \n***validation of model f");
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/SupportApexPolicyModelCreator.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/SupportApexPolicyModelCreator.java
new file mode 100644
index 000000000..85040221a
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/handling/SupportApexPolicyModelCreator.java
@@ -0,0 +1,406 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.handling;
+
+import java.util.Map;
+import java.util.UUID;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInformation;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.test.TestApexModelCreator;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbums;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvents;
+import org.onap.policy.apex.model.eventmodel.concepts.AxField;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicies;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicy;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateOutput;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskOutputType;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskReference;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskParameter;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskSelectionLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxTasks;
+
+/**
+ * Model creator for model tests.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class SupportApexPolicyModelCreator implements TestApexModelCreator<AxPolicyModel> {
+
+    @Override
+    public AxPolicyModel getModel() {
+        final AxContextSchema schema0 = new AxContextSchema(new AxArtifactKey("eventContextItem0", "0.0.1"), "Java",
+                        "java.lang.String");
+        final AxContextSchema schema1 = new AxContextSchema(new AxArtifactKey("eventContextItem1", "0.0.1"), "Java",
+                        "java.lang.Long");
+        final AxContextSchema schema2 = new AxContextSchema(new AxArtifactKey("StringType", "0.0.1"), "Java",
+                        "org.onap.policy.apex.model.policymodel.concepts.TestContextItem000");
+        final AxContextSchema schema3 = new AxContextSchema(new AxArtifactKey("MapType", "0.0.1"), "Java",
+                        "org.onap.policy.apex.model.policymodel.concepts.TestContextItem00A");
+
+        final AxContextSchemas schemas = new AxContextSchemas(new AxArtifactKey("ContextSchemas", "0.0.1"));
+        schemas.getSchemasMap().put(schema0.getKey(), schema0);
+        schemas.getSchemasMap().put(schema1.getKey(), schema1);
+        schemas.getSchemasMap().put(schema2.getKey(), schema2);
+        schemas.getSchemasMap().put(schema3.getKey(), schema3);
+
+        final AxContextAlbum album0 = new AxContextAlbum(new AxArtifactKey("contextAlbum0", "0.0.1"), "APPLICATION",
+                        true, schema3.getKey());
+        final AxContextAlbum album1 = new AxContextAlbum(new AxArtifactKey("contextAlbum1", "0.0.1"), "GLOBAL", false,
+                        schema2.getKey());
+
+        final AxContextAlbums albums = new AxContextAlbums(new AxArtifactKey("context", "0.0.1"));
+        albums.getAlbumsMap().put(album0.getKey(), album0);
+        albums.getAlbumsMap().put(album1.getKey(), album1);
+
+        final AxEvent inEvent = new AxEvent(new AxArtifactKey("inEvent", "0.0.1"),
+                        "org.onap.policy.apex.model.policymodel.events", "Source", "Target");
+        inEvent.getParameterMap().put("IEPAR0",
+                        new AxField(new AxReferenceKey(inEvent.getKey(), "IEPAR0"), schema0.getKey()));
+        inEvent.getParameterMap().put("IEPAR1",
+                        new AxField(new AxReferenceKey(inEvent.getKey(), "IEPAR1"), schema1.getKey()));
+
+        final AxEvent outEvent0 = new AxEvent(new AxArtifactKey("outEvent0", "0.0.1"),
+                        "org.onap.policy.apex.model.policymodel.events", "Source", "Target");
+        outEvent0.getParameterMap().put("OE0PAR0",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE0PAR0"), schema0.getKey()));
+        outEvent0.getParameterMap().put("OE0PAR1",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE0PAR1"), schema1.getKey()));
+        outEvent0.getParameterMap().put("OE1PAR0",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE1PAR0"), schema0.getKey()));
+        outEvent0.getParameterMap().put("OE1PAR1",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE1PAR1"), schema1.getKey()));
+
+        final AxEvent outEvent1 = new AxEvent(new AxArtifactKey("outEvent1", "0.0.1"),
+                        "org.onap.policy.apex.model.policymodel.events", "Source", "Target");
+        outEvent1.getParameterMap().put("OE1PAR0",
+                        new AxField(new AxReferenceKey(outEvent1.getKey(), "OE1PAR0"), schema0.getKey()));
+        outEvent1.getParameterMap().put("OE1PAR1",
+                        new AxField(new AxReferenceKey(outEvent1.getKey(), "OE1PAR1"), schema1.getKey()));
+
+        final AxEvents events = new AxEvents(new AxArtifactKey("events", "0.0.1"));
+        events.getEventMap().put(inEvent.getKey(), inEvent);
+        events.getEventMap().put(outEvent0.getKey(), outEvent0);
+        events.getEventMap().put(outEvent1.getKey(), outEvent1);
+
+        final AxTask task = new AxTask(new AxArtifactKey("task", "0.0.1"));
+
+        task.setInputEvent(inEvent);
+        task.setOutputEvents(Map.of(outEvent0.getId(), outEvent0, outEvent1.getId(), outEvent1));
+
+        final AxTaskParameter taskPar0 = new AxTaskParameter(new AxReferenceKey(task.getKey(), "taskParameter0"),
+                        "Task parameter 0 value");
+        final AxTaskParameter taskPar1 = new AxTaskParameter(new AxReferenceKey(task.getKey(), "taskParameter1"),
+                        "Task parameter 1 value");
+
+        task.getTaskParameters().put(taskPar0.getKey().getLocalName(), taskPar0);
+        task.getTaskParameters().put(taskPar1.getKey().getLocalName(), taskPar1);
+        task.getContextAlbumReferences().add(album0.getKey());
+        task.getContextAlbumReferences().add(album1.getKey());
+
+        final AxTaskLogic taskLogic = new AxTaskLogic(new AxReferenceKey(task.getKey(), "taskLogic"), "MVEL",
+                        "Some task logic");
+        task.setTaskLogic(taskLogic);
+
+        final AxTasks tasks = new AxTasks(new AxArtifactKey("tasks", "0.0.1"));
+        tasks.getTaskMap().put(task.getKey(), task);
+
+        final AxPolicy policy = new AxPolicy(new AxArtifactKey("policy", "0.0.1"));
+        policy.setTemplate("FREEFORM");
+
+        final AxState state = new AxState(new AxReferenceKey(policy.getKey(), "state"));
+        final AxTaskSelectionLogic taskSelectionLogic = new AxTaskSelectionLogic(
+                        new AxReferenceKey(state.getKey(), "taskSelectionLogic"), "MVEL", "Some TS logic ");
+
+        state.setTrigger(inEvent.getKey());
+        state.getContextAlbumReferences().add(album0.getKey());
+        state.getContextAlbumReferences().add(album1.getKey());
+        state.setTaskSelectionLogic(taskSelectionLogic);
+        state.setDefaultTask(task.getKey());
+
+        final AxStateOutput stateOutput0 = new AxStateOutput(new AxReferenceKey(state.getKey(), "stateOutput0"),
+                        outEvent0.getKey(), AxReferenceKey.getNullKey());
+        state.getStateOutputs().put(stateOutput0.getKey().getLocalName(), stateOutput0);
+
+        final AxStateTaskReference stateTaskReference = new AxStateTaskReference(
+                        new AxReferenceKey(state.getKey(), task.getKey().getName()), AxStateTaskOutputType.DIRECT,
+                        stateOutput0.getKey());
+
+        state.getTaskReferences().put(task.getKey(), stateTaskReference);
+
+        policy.getStateMap().put(state.getKey().getLocalName(), state);
+        policy.setFirstState(state.getKey().getLocalName());
+
+        final AxPolicies policies = new AxPolicies(new AxArtifactKey("policies", "0.0.1"));
+        policies.getPolicyMap().put(policy.getKey(), policy);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKey", "0.0.1"));
+        final AxPolicyModel policyModel = new AxPolicyModel(new AxArtifactKey("PolicyModel", "0.0.1"));
+        policyModel.setKeyInformation(keyInformation);
+        policyModel.setSchemas(schemas);
+        policyModel.setAlbums(albums);
+        policyModel.setEvents(events);
+        policyModel.setTasks(tasks);
+        policyModel.setPolicies(policies);
+        policyModel.getKeyInformation().generateKeyInfo(policyModel);
+
+        int uuidIncrementer = 0;
+        for (final AxKeyInfo keyInfo : policyModel.getKeyInformation().getKeyInfoMap().values()) {
+            final String uuidString = String.format("ce9168c-e6df-414f-9646-6da464b6e%03d", uuidIncrementer++);
+            keyInfo.setUuid(UUID.fromString(uuidString));
+        }
+
+        final AxValidationResult result = new AxValidationResult();
+        policyModel.validate(result);
+
+        return policyModel;
+    }
+
+    /**
+     * Gets another policy model.
+     *
+     * @return the model
+     */
+    public AxPolicyModel getAnotherModel() {
+        final AxContextSchema schema0 = new AxContextSchema(new AxArtifactKey("eventContextItemA0", "0.0.1"), "Java",
+                        "java.lang.String");
+        final AxContextSchema schema1 = new AxContextSchema(new AxArtifactKey("eventContextItemA1", "0.0.1"), "Java",
+                        "java.lang.Long");
+        final AxContextSchema schema2 = new AxContextSchema(new AxArtifactKey("StringTypeA", "0.0.1"), "Java",
+                        "org.onap.policy.apex.model.policymodel.concepts.TestContextItem000");
+        final AxContextSchema schema3 = new AxContextSchema(new AxArtifactKey("MapTypeA", "0.0.1"), "Java",
+                        "org.onap.policy.apex.model.policymodel.concepts.TestContextItem00A");
+
+        final AxContextSchemas schemas = new AxContextSchemas(new AxArtifactKey("ContextSchemasA", "0.0.1"));
+        schemas.getSchemasMap().put(schema0.getKey(), schema0);
+        schemas.getSchemasMap().put(schema1.getKey(), schema1);
+        schemas.getSchemasMap().put(schema2.getKey(), schema2);
+        schemas.getSchemasMap().put(schema3.getKey(), schema3);
+
+        final AxContextAlbum album0 = new AxContextAlbum(new AxArtifactKey("contextAlbumA0", "0.0.1"), "APPLICATION",
+                        true, schema3.getKey());
+        final AxContextAlbum album1 = new AxContextAlbum(new AxArtifactKey("contextAlbumA1", "0.0.1"), "GLOBAL", false,
+                        schema2.getKey());
+
+        final AxContextAlbums albums = new AxContextAlbums(new AxArtifactKey("contextA", "0.0.1"));
+        albums.getAlbumsMap().put(album0.getKey(), album0);
+        albums.getAlbumsMap().put(album1.getKey(), album1);
+
+        final AxEvent inEvent = new AxEvent(new AxArtifactKey("inEventA", "0.0.1"),
+                        "org.onap.policy.apex.model.policymodel.events", "Source", "Target");
+        inEvent.getParameterMap().put("IEPARA0",
+                        new AxField(new AxReferenceKey(inEvent.getKey(), "IEPARA0"), schema0.getKey()));
+        inEvent.getParameterMap().put("IEPARA1",
+                        new AxField(new AxReferenceKey(inEvent.getKey(), "IEPARA1"), schema1.getKey()));
+
+        final AxEvent outEvent0 = new AxEvent(new AxArtifactKey("outEventA0", "0.0.1"),
+                        "org.onap.policy.apex.model.policymodel.events", "Source", "Target");
+        outEvent0.getParameterMap().put("OE0PARA0",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE0PARA0"), schema0.getKey()));
+        outEvent0.getParameterMap().put("OE0PARA1",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE0PARA1"), schema1.getKey()));
+        outEvent0.getParameterMap().put("OE1PARA0",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE1PARA0"), schema0.getKey()));
+        outEvent0.getParameterMap().put("OE1PARA1",
+                        new AxField(new AxReferenceKey(outEvent0.getKey(), "OE1PARA1"), schema1.getKey()));
+
+        final AxEvent outEvent1 = new AxEvent(new AxArtifactKey("outEventA1", "0.0.1"),
+                        "org.onap.policy.apex.model.policymodel.events", "Source", "Target");
+        outEvent1.getParameterMap().put("OE1PARA0",
+                        new AxField(new AxReferenceKey(outEvent1.getKey(), "OE1PARA0"), schema0.getKey()));
+        outEvent1.getParameterMap().put("OE1PARA1",
+                        new AxField(new AxReferenceKey(outEvent1.getKey(), "OE1PARA1"), schema1.getKey()));
+
+        final AxEvents events = new AxEvents(new AxArtifactKey("eventsA", "0.0.1"));
+        events.getEventMap().put(inEvent.getKey(), inEvent);
+        events.getEventMap().put(outEvent0.getKey(), outEvent0);
+        events.getEventMap().put(outEvent1.getKey(), outEvent1);
+
+        final AxTask task = new AxTask(new AxArtifactKey("taskA", "0.0.1"));
+
+        task.setInputEvent(inEvent);
+        task.setOutputEvents(Map.of(outEvent0.getId(), outEvent0, outEvent1.getId(), outEvent1));
+
+        final AxTaskParameter taskPar0 = new AxTaskParameter(new AxReferenceKey(task.getKey(), "taskParameterA0"),
+                        "Task parameter 0 value");
+        final AxTaskParameter taskPar1 = new AxTaskParameter(new AxReferenceKey(task.getKey(), "taskParameterA1"),
+                        "Task parameter 1 value");
+
+        task.getTaskParameters().put(taskPar0.getKey().getLocalName(), taskPar0);
+        task.getTaskParameters().put(taskPar1.getKey().getLocalName(), taskPar1);
+        task.getContextAlbumReferences().add(album0.getKey());
+        task.getContextAlbumReferences().add(album1.getKey());
+
+        final AxTaskLogic taskLogic = new AxTaskLogic(new AxReferenceKey(task.getKey(), "taskLogicA"), "MVEL",
+                        "Some task logic");
+        task.setTaskLogic(taskLogic);
+
+        final AxTasks tasks = new AxTasks(new AxArtifactKey("tasksA", "0.0.1"));
+        tasks.getTaskMap().put(task.getKey(), task);
+
+        final AxPolicy policy = new AxPolicy(new AxArtifactKey("policyA", "0.0.1"));
+        policy.setTemplate("FREEFORM");
+
+        final AxState state = new AxState(new AxReferenceKey(policy.getKey(), "stateA"));
+        final AxTaskSelectionLogic taskSelectionLogic = new AxTaskSelectionLogic(
+                        new AxReferenceKey(state.getKey(), "taskSelectionLogicA"), "MVEL", "Some TS logic ");
+
+        state.setTrigger(inEvent.getKey());
+        state.getContextAlbumReferences().add(album0.getKey());
+        state.getContextAlbumReferences().add(album1.getKey());
+        state.setTaskSelectionLogic(taskSelectionLogic);
+        state.setDefaultTask(task.getKey());
+
+        final AxStateOutput stateOutput0 = new AxStateOutput(new AxReferenceKey(state.getKey(), "stateOutputA0"),
+                        outEvent0.getKey(), AxReferenceKey.getNullKey());
+        state.getStateOutputs().put(stateOutput0.getKey().getLocalName(), stateOutput0);
+
+        final AxStateTaskReference stateTaskReference = new AxStateTaskReference(
+                        new AxReferenceKey(state.getKey(), task.getKey().getName()), AxStateTaskOutputType.DIRECT,
+                        stateOutput0.getKey());
+
+        state.getTaskReferences().put(task.getKey(), stateTaskReference);
+
+        policy.getStateMap().put(state.getKey().getLocalName(), state);
+        policy.setFirstState(state.getKey().getLocalName());
+
+        final AxPolicies policies = new AxPolicies(new AxArtifactKey("policiesA", "0.0.1"));
+        policies.getPolicyMap().put(policy.getKey(), policy);
+
+        final AxKeyInformation keyInformation = new AxKeyInformation(new AxArtifactKey("KeyInfoMapKeyA", "0.0.1"));
+        final AxPolicyModel policyModel = new AxPolicyModel(new AxArtifactKey("PolicyModelA", "0.0.1"));
+        policyModel.setKeyInformation(keyInformation);
+        policyModel.setSchemas(schemas);
+        policyModel.setAlbums(albums);
+        policyModel.setEvents(events);
+        policyModel.setTasks(tasks);
+        policyModel.setPolicies(policies);
+        policyModel.getKeyInformation().generateKeyInfo(policyModel);
+
+        int uuidIncrementer = 0;
+        for (final AxKeyInfo keyInfo : policyModel.getKeyInformation().getKeyInfoMap().values()) {
+            final String uuidString = String.format("ce9168c-e6df-414f-9646-6da464b6e%03d", uuidIncrementer++);
+            keyInfo.setUuid(UUID.fromString(uuidString));
+        }
+
+        final AxValidationResult result = new AxValidationResult();
+        policyModel.validate(result);
+
+        return policyModel;
+    }
+
+    @Override
+    public AxPolicyModel getMalstructuredModel() {
+        final AxPolicyModel policyModel = new AxPolicyModel(new AxArtifactKey("policyModel", "0.0.1"));
+        return policyModel;
+    }
+
+    @Override
+    public AxPolicyModel getObservationModel() {
+        final AxPolicyModel policyModel = getModel();
+
+        final AxState state = policyModel.getPolicies().get("policy").getStateMap().get("state");
+        final AxTask task = policyModel.getTasks().get("task");
+
+        final AxStateFinalizerLogic stateFinalizerLogic = new AxStateFinalizerLogic(
+                        new AxReferenceKey(state.getKey(), "SFL"), "MVEL", "Some SF logic ");
+        state.getStateFinalizerLogicMap().put(stateFinalizerLogic.getKey().getLocalName(), stateFinalizerLogic);
+        final AxStateTaskReference stateTaskReference = new AxStateTaskReference(
+                        new AxReferenceKey(state.getKey(), task.getKey().getName()), AxStateTaskOutputType.LOGIC,
+                        stateFinalizerLogic.getKey());
+
+        state.getTaskReferences().put(task.getKey(), stateTaskReference);
+
+        return policyModel;
+    }
+
+    @Override
+    public AxPolicyModel getWarningModel() {
+        final AxPolicyModel policyModel = getModel();
+
+        final AxState anotherState = new AxState(
+                        new AxReferenceKey(new AxArtifactKey("policy", "0.0.1"), "anotherState"));
+
+        final AxEvent inEvent = policyModel.getEvents().getEventMap().get(new AxArtifactKey("inEvent", "0.0.1"));
+        final AxEvent outEvent0 = policyModel.getEvents().getEventMap().get(new AxArtifactKey("outEvent0", "0.0.1"));
+
+        final AxTask anotherTask = new AxTask(new AxArtifactKey("anotherTask", "0.0.1"));
+
+        anotherTask.setInputEvent(inEvent);
+        anotherTask.setOutputEvents(Map.of(outEvent0.getId(), outEvent0));
+        final AxTaskParameter taskPar0 = new AxTaskParameter(new AxReferenceKey(anotherTask.getKey(), "taskParameter0"),
+                        "Task parameter 0 value");
+        final AxTaskParameter taskPar1 = new AxTaskParameter(new AxReferenceKey(anotherTask.getKey(), "taskParameter1"),
+                        "Task parameter 1 value");
+
+        anotherTask.getTaskParameters().put(taskPar0.getKey().getLocalName(), taskPar0);
+        anotherTask.getTaskParameters().put(taskPar1.getKey().getLocalName(), taskPar1);
+
+        final AxTaskLogic taskLogic = new AxTaskLogic(new AxReferenceKey(anotherTask.getKey(), "taskLogic"), "MVEL",
+                        "Some task logic");
+        anotherTask.setTaskLogic(taskLogic);
+        policyModel.getTasks().getTaskMap().put(anotherTask.getKey(), anotherTask);
+
+        final AxStateOutput anotherStateOutput0 = new AxStateOutput(
+                        new AxReferenceKey(anotherState.getKey(), "stateOutput0"), outEvent0.getKey(),
+                        AxReferenceKey.getNullKey());
+        anotherState.setTrigger(inEvent.getKey());
+        anotherState.getStateOutputs().put(anotherStateOutput0.getKey().getLocalName(), anotherStateOutput0);
+        anotherState.setDefaultTask(anotherTask.getKey());
+        final AxStateTaskReference anotherStateTaskReference = new AxStateTaskReference(
+                        new AxReferenceKey(anotherState.getKey(), anotherTask.getKey().getName()),
+                        AxStateTaskOutputType.DIRECT, anotherStateOutput0.getKey());
+        anotherState.getTaskReferences().put(anotherTask.getKey(), anotherStateTaskReference);
+
+        policyModel.getPolicies().getPolicyMap().get(new AxArtifactKey("policy", "0.0.1")).getStateMap()
+                        .put(anotherState.getKey().getLocalName(), anotherState);
+
+        policyModel.getKeyInformation().generateKeyInfo(policyModel);
+
+        return policyModel;
+    }
+
+    @Override
+    public AxPolicyModel getInvalidModel() {
+        final AxPolicyModel policyModel = getModel();
+
+        policyModel.getAlbums().get(new AxArtifactKey("contextAlbum0", "0.0.1")).setScope("UNDEFINED");
+        policyModel.getAlbums().get(new AxArtifactKey("contextAlbum1", "0.0.1")).setScope("UNDEFINED");
+
+        final AxEvent outEvent0 = policyModel.getEvents().get("outEvent0");
+        outEvent0.getParameterMap().remove("OE1PAR0");
+        outEvent0.getParameterMap().remove("OE1PAR1");
+
+        return policyModel;
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/policymodel/utils/SupportPolicyModelValidator.java b/model/src/test/java/org/onap/policy/apex/model/policymodel/utils/SupportPolicyModelValidator.java
new file mode 100644
index 000000000..daff1efa7
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/policymodel/utils/SupportPolicyModelValidator.java
@@ -0,0 +1,48 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.policymodel.utils;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelException;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelReader;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+
+/**
+ * Main class to run the policy model validator.
+ */
+public class SupportPolicyModelValidator {
+    /**
+     * Main method.
+     * @param args the command line arguments
+     * @throws ApexModelException on errors on the apex model
+     * @throws FileNotFoundException on file find failures
+     */
+    public static void main(final String[] args) throws ApexModelException, FileNotFoundException {
+        final ApexModelReader<AxPolicyModel> policyModelReader = new ApexModelReader<AxPolicyModel>(
+                        AxPolicyModel.class);
+
+        final AxPolicyModel policyModel = policyModelReader.read(new FileInputStream(args[0]));
+        final AxValidationResult result = policyModel.validate(new AxValidationResult());
+        System.out.println(result);
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/CollectionUtilitiesTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/CollectionUtilitiesTest.java
new file mode 100644
index 000000000..2512133e7
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/CollectionUtilitiesTest.java
@@ -0,0 +1,87 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.Test;
+
+public class CollectionUtilitiesTest {
+
+    @Test
+    public void testNullLists() {
+        int result = 0;
+
+        result = CollectionUtils.compareLists(null, null);
+        assertEquals(0, result);
+
+        List<String> leftList = new ArrayList<String>();
+
+        result = CollectionUtils.compareLists(leftList, null);
+        assertEquals(-1, result);
+
+        List<String> rightList = new ArrayList<String>();
+
+        result = CollectionUtils.compareLists(null, rightList);
+        assertEquals(1, result);
+
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(0, result);
+
+        leftList.add("AAA");
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(-1, result);
+
+        rightList.add("AAA");
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(0, result);
+
+        rightList.add("BBB");
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(1, result);
+
+        leftList.add("BBB");
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(0, result);
+
+        leftList.add("CCA");
+        rightList.add("CCB");
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(-1, result);
+
+        leftList.remove(leftList.size() - 1);
+        rightList.remove(rightList.size() - 1);
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(0, result);
+
+        leftList.add("CCB");
+        rightList.add("CCA");
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(1, result);
+
+        leftList.remove(leftList.size() - 1);
+        rightList.remove(rightList.size() - 1);
+        result = CollectionUtils.compareLists(leftList, rightList);
+        assertEquals(0, result);
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/DirectoryUtilsTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/DirectoryUtilsTest.java
new file mode 100644
index 000000000..69c2d4763
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/DirectoryUtilsTest.java
@@ -0,0 +1,55 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities;
+
+import static org.junit.Assert.assertNotNull;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.Arrays;
+import org.junit.Test;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+public class DirectoryUtilsTest {
+
+    @Test
+    public void test() throws IOException {
+        DirectoryUtils.emptyDirectory(new File("/i/dont/exist"));
+
+        File tempDir = Files.createTempDirectory("test").toFile();
+        assertNotNull(tempDir);
+
+        Files.createTempDirectory(tempDir.toPath(), "testsubprefix");
+
+        TextFileUtils.putStringAsTextFile("Temp File 0 contents", tempDir.getAbsolutePath() + "/tempFile0.tmp");
+        TextFileUtils.putStringAsTextFile("Temp File 1 contents", tempDir.getAbsolutePath() + "/tempFile1.tmp");
+
+        DirectoryUtils.emptyDirectory(tempDir);
+
+        DirectoryUtils.getLocalTempDirectory(null);
+
+        byte[] byteArray = new byte[] {0, 0, 0};
+        DirectoryUtils.getLocalTempDirectory(Arrays.toString(byteArray));
+    }
+
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/KeyComparerTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/KeyComparerTest.java
new file mode 100644
index 000000000..20780b271
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/KeyComparerTest.java
@@ -0,0 +1,53 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+
+import org.junit.Test;
+import org.onap.policy.apex.model.utilities.comparison.KeyComparer;
+import org.onap.policy.apex.model.utilities.comparison.KeyDifference;
+
+/**
+ * Test key comparisons.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class KeyComparerTest {
+
+    @Test
+    public void test() {
+        KeyDifference<String> keyDifference = new KeyComparer<String>().compareKeys("Hello", "Goodbye");
+
+        assertFalse(keyDifference.isEqual());
+        assertEquals("Hello", keyDifference.getLeftKey().toString());
+        assertEquals("Goodbye", keyDifference.getRightKey().toString());
+
+        assertEquals("left key Hello and right key Goodbye differ\n", keyDifference.asString(true));
+        assertEquals("left key Hello and right key Goodbye differ\n", keyDifference.asString(false));
+
+        KeyDifference<String> keyDifference2 = new KeyComparer<String>().compareKeys("Here", "Here");
+        assertEquals("", keyDifference2.asString(true));
+        assertEquals("left key Here equals right key Here\n", keyDifference2.asString(false));
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/KeyedMapComparerTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/KeyedMapComparerTest.java
new file mode 100644
index 000000000..b4e88e20d
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/KeyedMapComparerTest.java
@@ -0,0 +1,76 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.TreeMap;
+import org.junit.Test;
+import org.onap.policy.apex.model.utilities.comparison.KeyedMapComparer;
+import org.onap.policy.apex.model.utilities.comparison.KeyedMapDifference;
+
+/**
+ * Test key map comparisons.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class KeyedMapComparerTest {
+
+    @Test
+    public void test() {
+        TreeMap<String, String> leftMap = new TreeMap<String, String>();
+        leftMap.put("B", "BBBBB");
+        leftMap.put("C", "CCCCC");
+        leftMap.put("E", "EEEEE");
+        leftMap.put("G", "GGGGG");
+
+        TreeMap<String, String> rightMap = new TreeMap<String, String>();
+        rightMap.put("A", "AAAAA");
+        rightMap.put("B", "B");
+        rightMap.put("D", "DDDDD");
+        rightMap.put("E", "EEEEE");
+        rightMap.put("F", "FFFFF");
+        rightMap.put("G", "G");
+
+        KeyedMapDifference<String, String> kmComparedSame =
+                new KeyedMapComparer<String, String>().compareMaps(leftMap, leftMap);
+        KeyedMapDifference<String, String> kmComparedDiff =
+                new KeyedMapComparer<String, String>().compareMaps(leftMap, rightMap);
+
+        assertEquals(leftMap, kmComparedSame.getIdenticalValues());
+        assertEquals(1, kmComparedDiff.getLeftOnly().size());
+        assertEquals(3, kmComparedDiff.getRightOnly().size());
+        assertEquals(2, kmComparedDiff.getDifferentValues().size());
+        assertEquals(1, kmComparedDiff.getIdenticalValues().size());
+
+        assertNotNull(kmComparedSame.asString(true, true));
+        assertNotNull(kmComparedSame.asString(true, false));
+        assertNotNull(kmComparedSame.asString(false, false));
+        assertNotNull(kmComparedSame.asString(false, true));
+
+        assertNotNull(kmComparedDiff.asString(true, true));
+        assertNotNull(kmComparedDiff.asString(true, false));
+        assertNotNull(kmComparedDiff.asString(false, false));
+        assertNotNull(kmComparedDiff.asString(false, true));
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/TextFileUtilsTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/TextFileUtilsTest.java
new file mode 100644
index 000000000..1d6f29fe5
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/TextFileUtilsTest.java
@@ -0,0 +1,56 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import org.junit.Test;
+import org.onap.policy.common.utils.resources.TextFileUtils;
+
+/**
+ * Test text file utilities.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class TextFileUtilsTest {
+
+    private static final String FILE_CONTENT = "This is the contents of a text file";
+
+    @Test
+    public void test() throws IOException {
+        final File tempTextFile = File.createTempFile("Test", "txt");
+
+        TextFileUtils.putStringAsTextFile(FILE_CONTENT, tempTextFile.getAbsolutePath());
+
+        final String textFileString0 = TextFileUtils.getTextFileAsString(tempTextFile.getAbsolutePath());
+        assertEquals(FILE_CONTENT, textFileString0);
+
+        final FileInputStream fis = new FileInputStream(tempTextFile);
+        final String textFileString1 = TextFileUtils.getStreamAsString(fis);
+        assertEquals(textFileString0, textFileString1);
+
+    }
+
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/TreeMapUtilsTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/TreeMapUtilsTest.java
new file mode 100644
index 000000000..c3a36b7b9
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/TreeMapUtilsTest.java
@@ -0,0 +1,157 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.TreeMap;
+import org.junit.Test;
+
+/**
+ * Test the tree map utilities.
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class TreeMapUtilsTest {
+
+    private static final int KEY1 = 10;
+    private static final int KEY2 = 20;
+    private static final int KEY3 = 30;
+    private static final String VALUE1 = "a-one";
+    private static final String VALUE2 = "b-two";
+    private static final String VALUE3 = "c-three";
+    private static final String VALUE4 = "d-four";
+
+    @Test
+    public void testFindMatchingEntries() {
+        TreeMap<String, String> testTreeMap = new TreeMap<String, String>();
+        testTreeMap.put("G", "G");
+        testTreeMap.put("H", "H");
+        testTreeMap.put("JA", "JA");
+        testTreeMap.put("JAM", "JAM");
+        testTreeMap.put("JOE", "JOE");
+        testTreeMap.put("JOSH", "JOSH");
+        testTreeMap.put("K", "K");
+
+        List<Entry<String, String>> foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "F");
+        assertEquals(0, foundKeyList.size());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "G");
+        assertEquals("G", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "H");
+        assertEquals("H", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "I");
+        assertEquals(0, foundKeyList.size());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "J");
+        assertEquals("JA", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "JA");
+        assertEquals("JA", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "JB");
+        assertEquals(0, foundKeyList.size());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "JO");
+        assertEquals("JOE", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "JOE");
+        assertEquals("JOE", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "JOS");
+        assertEquals("JOSH", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "JOSH");
+        assertEquals("JOSH", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "K");
+        assertEquals("K", foundKeyList.get(0).getKey());
+
+        foundKeyList = TreeMapUtils.findMatchingEntries(testTreeMap, "L");
+        assertEquals(0, foundKeyList.size());
+    }
+
+    @Test
+    public void testCompareMaps() {
+        Map<Integer, String> map1 = Map.of();
+        Map<Integer, String> map2 = Map.of();
+
+        // note: using TreeMap so we can control the ordering of the entries
+
+        // compare with self
+        assertThat(TreeMapUtils.compareMaps(map1, map1)).isZero();
+
+        // two empty maps
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isZero();
+
+        // same content
+        map1 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE3));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE3));
+        assertThat(TreeMapUtils.compareMaps(map1, map1)).isZero();
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isZero();
+
+        // one is shorter than the other
+        map1 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE3));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+
+        // first key is different
+        map1 = new TreeMap<>(Map.of(KEY3, VALUE1, KEY2, VALUE2));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+
+        // second key is different
+        map1 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY3, VALUE2));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+
+        // first value is different
+        map1 = new TreeMap<>(Map.of(KEY1, VALUE4, KEY2, VALUE2, KEY3, VALUE3));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE3));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+
+        // second value is different
+        map1 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE4, KEY3, VALUE3));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE3));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+
+        // third value is different
+        map1 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE4));
+        map2 = new TreeMap<>(Map.of(KEY1, VALUE1, KEY2, VALUE2, KEY3, VALUE3));
+        assertThat(TreeMapUtils.compareMaps(map1, map2)).isPositive();
+        assertThat(TreeMapUtils.compareMaps(map2, map1)).isNegative();
+    }
+}
diff --git a/model/src/test/java/org/onap/policy/apex/model/utilities/json/JsonHandlerTest.java b/model/src/test/java/org/onap/policy/apex/model/utilities/json/JsonHandlerTest.java
new file mode 100644
index 000000000..ae5d53ec3
--- /dev/null
+++ b/model/src/test/java/org/onap/policy/apex/model/utilities/json/JsonHandlerTest.java
@@ -0,0 +1,59 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.utilities.json;
+
+import static org.junit.Assert.assertEquals;
+
+import com.google.gson.GsonBuilder;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import org.junit.Test;
+
+public class JsonHandlerTest {
+
+    private static final String VALUE = "value";
+
+    @Test
+    public void testAssertions() throws IOException {
+        final OverTheMoonObject jsonObject = new OverTheMoonObject(VALUE);
+        final String jsonString = new GsonBuilder().create().toJson(jsonObject);
+
+        final byte[] bytes = jsonString.getBytes(StandardCharsets.UTF_8);
+        try (final InputStream inputStream = new ByteArrayInputStream(bytes);) {
+
+            final JsonHandler<OverTheMoonObject> objUnderTest = new JsonHandler<>();
+
+            final OverTheMoonObject actualObject = objUnderTest.read(OverTheMoonObject.class, inputStream);
+            assertEquals(VALUE, actualObject.name);
+        }
+
+    }
+
+    private class OverTheMoonObject {
+        private final String name;
+
+        public OverTheMoonObject(final String name) {
+            this.name = name;
+        }
+    }
+}