Composite Refactorings for EMF Models

Models are primary artifacts in model-based, and especially, in model-driven software development processes. Due to their central role, the quality of models must be high to lead to software products of high quality. A common technique for improving the quality of software artifacts is refactoring. Originally developed for code structure improvement, the concept of refactoring has been raised to the level of models. Especially for the UML, a lot of model refactorings have been proposed in the literature. A number of these refactorings are composed from more primitive ones. In this paper, we present a model-driven approach to the development of composite refactorings for EMF models. The specification of composite refactorings is based on a set of atomic refactorings and a domain-specific language, called CoMReL, to specify their composition. Generated model refactorings use the Eclipse Modeling Framework and further Eclipse technologies as platform. From the application point of view, composite and atomic refactorings cannot be distinguished. Specification language CoMReL as well as its supporting tool environment are evaluated at the model-driven development of a variety of composite UML and EMF model refactorings.