diff --git a/src/component.js b/src/component.js
index 0865c1c..1cae2ea 100644
--- a/src/component.js
+++ b/src/component.js
@@ -103,13 +103,6 @@ class Component {
 
           return this.mainComponentObj;
      }
-
-     /**
-      * @function addAttrTypeRefClassSchema
-      * @description Add schema of such classes of which attribute type is refference of UMLClass
-      * @param {Array} refClasses
-      * @memberof Component
-      */
      addAttrTypeRefClassSchema(refClasses) {
           refClasses.forEach(objClass => {
                let mainClassesObj = {};
@@ -143,18 +136,6 @@ class Component {
 
           });
      }
-
-     /**
-      * @function addClassSchema
-      * @description Add schema of such classes of which attribute type is refference of UMLClass
-      * @param {Array} classEleOrViews
-      * @param {Object} assoClassLink 
-      * @param {Object} mAssoClassLinkView 
-      * @param {Array} arrIdClasses 
-      * @param {Array} duplicateDeletedReference 
-      * @param {Array} duplicatePropertyError
-      * @memberof Component
-      */
      addClassSchema(classEleOrViews, assoClassLink, mAssoClassLinkView, arrIdClasses, duplicateDeletedReference, duplicatePropertyError) {
           classEleOrViews.forEach(classEleOrView => {
                let mainClassesObj = {};
@@ -220,7 +201,35 @@ class Component {
                let compositionRef = [];
 
                let arrAttributes = properties.getAttributes();
-
+               let arrEnumerations = properties.getEnumerations();
+               arrEnumerations.forEach(enumeration => {
+                    if(this.mainSchemaObj[enumeration.name] == null){
+                        let enumerationObj = {}
+                        enumerationObj.enum = utils.getEnumerationLiteral(enumeration);
+                        enumerationObj.description = enumerationObj.documentation ? utils.buildDescription(enumerationObj.documentation) : constant.STR_MISSING_DESCRIPTION;
+                        enumerationObj.type = 'string';
+                        if(enumerationObj.enum.length == 0) {
+                            /**
+                             * Check if the enumeration has a tag named 'ref'. If it presents use it as '$ref' value instead of including the enum to the specification
+                             */
+                            let refTag;
+                            if(enumeration.tags != null && enumeration.tags.length > 0 ){
+                                forEach(enumeration.tags, function (tag) {
+                                    if(tag.name === 'ref') {
+                                        refTag = tag.value;
+                                    }
+                                });
+                            }
+                            if( refTag != null) {
+                                enumerationObj = {}
+                                enumerationObj.$ref = refTag;
+                            } else {
+                                app.dialogs.showAlertDialog('Enumeration ' + enumeration.name + ' has no values. You can add the enumeration to the diagram to include it or specify "ref" tag to refer to the external definition.');
+                            }
+                        }
+                        this.mainSchemaObj[enumeration.name] = enumerationObj;
+                    }
+               });
 
                if (openAPI.isModelPackage()) {
                     /** 
@@ -372,14 +381,6 @@ class Component {
           });
      }
 
-     /**
-      * @function sortAssociationByModelExplorerSequence
-      * @description Add schema of such classes of which attribute type is refference of UMLClass
-      * @param {Array} objClass
-      * @param {Object} classAssociations 
-      * @returns {Array} newAssArr
-      * @memberof Component
-      */
      sortAssociationByModelExplorerSequence(objClass, classAssociations) {
           let newAssArr = [];
           let newClassAssociation = classAssociations;
@@ -408,7 +409,6 @@ class Component {
           newAssArr = newSort.concat(otherSort);
           return newAssArr;
      }
-
      /**
       * @function getJSONSchema
       * @description Returns component object 
diff --git a/src/properties.js b/src/properties.js
index ca4ae83..ce6ee8f 100644
--- a/src/properties.js
+++ b/src/properties.js
@@ -15,6 +15,7 @@ class Properties {
           this.objClass = objClass;
           this.assocSideClassLink = assocSideClassLink;
           this.arrAttRequired = [];
+          this.enumerations = [];
           utils.resetErrorBlock();
      }
 
@@ -28,6 +29,16 @@ class Properties {
           return this.arrAttRequired;
      }
 
+     /**
+       * @function getEnumerations
+       * @description Returns the array of enumerations used as data types by properties
+       * @returns {Array}
+       * @memberof Properties
+       */
+     getEnumerations() {
+           return this.enumerations;
+     }
+
      /**
       * @function addProperties
       * @description Adds properties to mainPropertiesObject
@@ -141,13 +152,22 @@ class Properties {
                               propertiesObj.minItems = 1;
                          }
                     } else {
-                         propertiesObj.description = (attribute.documentation ? utils.buildDescription(attribute.documentation) : constant.STR_MISSING_DESCRIPTION);
-
-                         utils.addAttributeType(propertiesObj, attribute);
-
+                         /**
+                          * If data type is enumeration, build allOf object with a reference to a corresponding schema
+                          */
                          if (attribute.type instanceof type.UMLEnumeration) {
-                              /* Add Enumeration */
-                              propertiesObj.enum = utils.getEnumerationLiteral(attribute.type);
+                              let allOfArr = [];
+                              let descriptionObj = {};
+                              let refObj = {};
+                              descriptionObj['description'] = attribute.documentation ? utils.buildDescription(attribute.documentation) : constant.STR_MISSING_DESCRIPTION;
+                              refObj['$ref'] = '#/components/schemas/' + attribute.type.name;
+                              _this.enumerations.push(attribute.type);
+                              allOfArr.push(descriptionObj);
+                              allOfArr.push(refObj);
+                              propertiesObj['allOf'] = allOfArr;
+                         } else{
+                             propertiesObj.description = (attribute.documentation ? utils.buildDescription(attribute.documentation) : constant.STR_MISSING_DESCRIPTION);
+                             utils.addAttributeType(propertiesObj, attribute);
                          }
                     }
                     if (attribute.defaultValue != "") {