Formal Semantics of Consistent EMF Model Transformations by Algebraic Graph Transformation

Model transformation is one of the key activities in model-driven software development. An increasingly popular technology to define modeling languages is provided by the Eclipse Modeling Framework (EMF). Several EMF model transformation approaches have been developed, focusing on different transformation aspects. To validate model transformations wrt. functional behavior and correctness, a formal foundation is needed. In this paper, we define EMF model transformations as a special kind of typed graph transformations using node type inheritance. Containment constraints of EMF model transformations are translated to a special kind of EMF model transformation rules such that their application leads to consistent transformation results only. Thus, we identify a kind of EMF model transformations which behave like algebraic graph transformations. As a consequence, the rich theory of algebraic graph transformation can be applied to these EMF model transformations to show functional behavior and correctness. Furthermore, we propose parallel graph transformation as a suitable framework for modeling EMF model transformations with multiobject structures. Multi-object structures at transformation rule level provide a flexible way to describe the transformation of structures with a flexible number of recurring structures, dependent on concrete model instances. Parallel graph transformation means parallelizing the application of model transformation rules at several occurences at once. We illustrate our approach by selected refactorings of simplified statechart models. Finally, we discuss the implementation of our concepts in a tool environment for EMF model transformations. 2 Enrico Biermann et al.