Towards a multi-view approach to model-driven refactoring

Model-driven engineering, an emerging trend in software engineering, has enabled the application of refactoring to UML models. One of the important steps in refactoring is the identification of refactoring opportunities within the model, also referred to as Model Smells. An Object-Oriented system modeled by UML is built up from many different views. Model refactoring, in recent proposals, is applied to a single view in the model. Hence information from other views are either not considered or later synchronized for consistency preservation. In this paper we outline an approach to refactor UML models using a multi-view approach. We exploit the inter-view relationship to suggest model smells by combining information from each UML view. We restrict our scope to one diagram from each UML view, class diagram (structural view), sequence diagram (behavioral view) and use case diagram (functional view). For each model smell, we describe (a) steps to detect the existence of the model smell (b) set of composite refactorings to remove the detected smell and (c) demonstration using a running example. We also propose a Multi-view Model Refactoring framework to realize the approach proposed in this paper.