diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java
index 2776604..0962ce2 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/DataConstraintModel.java
@@ -783,6 +783,15 @@
 		return resourceHierarchies.get(hierarchy);
 	}
 	
+	public ResourceHierarchy getOrPutResourceHierarchy(ResourceHierarchy resourceHierarchy) {
+		String hierarchy = resourceHierarchy.toString();
+		if (resourceHierarchies.get(hierarchy) != null) {
+			return resourceHierarchies.get(hierarchy);
+		}
+		resourceHierarchies.put(hierarchy, resourceHierarchy);
+		return resourceHierarchy;
+	}
+	
 	public List<ResourcePath> getResourcePaths() {
 		return resourcePaths;
 	}