Model driven development has become a promising trend in software development which makes models to the primary artifacts. However, code generators can produce high quality code only for input models being of high quality. On the other side, code refactoring is a well-known and investigated technique to improve software structures without changing the observable behaviour. So an essential technique for model quality assurance is the refactoring of models which is in focus of the current research.
Although several refactorings for models have been suggested, there is not yet a corresponding tool support in Eclipse for creating custom refactorings and applying them. Moreover, some model refactorings were adopted from code refactorings, especially for models that describe structural features like UML class diagrams. In addition, completely new approaches have been developed, especially for further diagram types such as state machines and activity diagrams or just other kinds of EMF models.