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diff --git a/model/src/main/java/org/onap/policy/apex/model/basicmodel/service/ModelService.java b/model/src/main/java/org/onap/policy/apex/model/basicmodel/service/ModelService.java
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+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019 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 java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexRuntimeException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
+
+/**
+ * The model service makes Apex models available to all classes in a JVM.
+ *
+ * <p>The reason for having a model service is to avoid having to pass concept and model definitions down long call
+ * chains in modules such as the Apex engine and editor. The model service makes the model and concept definitions
+ * available statically.
+ *
+ * <p>Note that the use of the model service means that only a single Apex model of a particular type may exist in Apex
+ * (particularly the engine) at any time. Of course the model in a JVM can be changed at any time provided all users of
+ * the model are stopped and restarted in an orderly manner.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public abstract class ModelService {
+    // The map holding the models
+    private static Map<Class<?>, AxConcept> modelMap = new ConcurrentHashMap<>();
+
+    /**
+     * This class is an abstract static class that cannot be extended.
+     */
+    private ModelService() {
+    }
+
+    /**
+     * Register a model with the model service.
+     *
+     * @param <M> the generic type
+     * @param modelClass the class of the model, used to index the model
+     * @param model The model
+     */
+    public static <M extends AxConcept> void registerModel(final Class<M> modelClass, final M model) {
+        modelMap.put(modelClass, model);
+    }
+
+    /**
+     * Remove a model from the model service.
+     *
+     * @param <M> the generic type
+     * @param modelClass the class of the model, used to index the model
+     */
+    public static <M extends AxConcept> void deregisterModel(final Class<M> modelClass) {
+        modelMap.remove(modelClass);
+    }
+
+    /**
+     * Get a model from the model service.
+     *
+     * @param <M> the generic type
+     * @param modelClass the class of the model, used to index the model
+     * @return The model
+     */
+    @SuppressWarnings("unchecked")
+    public static <M extends AxConcept> M getModel(final Class<M> modelClass) {
+        final M model = (M) modelMap.get(modelClass);
+
+        if (model == null) {
+            throw new ApexRuntimeException("Model for " + modelClass.getName() + " not found in model service");
+        }
+
+        return model;
+    }
+
+    /**
+     * Check if a model is defined on the model service.
+     *
+     * @param <M> the generic type
+     * @param modelClass the class of the model, used to index the model
+     * @return true if the model is defined
+     */
+    public static <M extends AxConcept> boolean existsModel(final Class<M> modelClass) {
+        return modelMap.get(modelClass) != null;
+    }
+
+    /**
+     * Clear all models in the model service.
+     */
+    public static void clear() {
+        modelMap.clear();
+    }
+}