diff --git a/li.strolch.model/src/main/java/li/strolch/model/ModelHelper.java b/li.strolch.model/src/main/java/li/strolch/model/ModelHelper.java
new file mode 100644
index 000000000..433e07cd1
--- /dev/null
+++ b/li.strolch.model/src/main/java/li/strolch/model/ModelHelper.java
@@ -0,0 +1,31 @@
+package li.strolch.model;
+
+import static li.strolch.model.StrolchModelConstants.BAG_PARAMETERS;
+import static li.strolch.model.StrolchModelConstants.BAG_RELATIONS;
+
+import li.strolch.model.parameter.StringParameter;
+
+/**
+ * Helper class to perform often performed model commands
+ */
+public class ModelHelper {
+
+	public static void copyExistingString(Resource src, Resource dst, String paramId) {
+		copyStringParam(src, dst, BAG_PARAMETERS, paramId);
+	}
+
+	public static void copyExistingRelation(Resource src, Resource dst, String paramId) {
+		copyStringParam(src, dst, BAG_RELATIONS, paramId);
+	}
+
+	public static void copyStringParam(Resource src, Resource dst, String bagId, String paramId) {
+		if (src.hasParameter(bagId, paramId) && !src.getStringP(bagId, paramId).isEmpty()) {
+			StringParameter existingBillingIdP = src.getStringP(bagId, paramId);
+			if (!dst.hasParameter(bagId, paramId)) {
+				dst.addParameter(existingBillingIdP.getClone());
+			} else if (dst.getStringP(bagId, paramId).isEmpty()) {
+				dst.setString(bagId, paramId, existingBillingIdP.getValue());
+			}
+		}
+	}
+}