Joachim Hössler, Michael Soden, Hajo Eichler. Coevolution of Models, Metamodels and Transformations. In Models and Human Reasoning. Wissenschaft und Technik Verlag, Berlin, 2005.
OMG’s MOF standard defines a four layer modelling architecture that enables software developers to quickly design their own domain specific modelling language. Using such language definitions (so called metamodels) it is possible to automatically derive model repositories where models conforming to that metamodel can be stored and accessed through standardized interfaces. Although this approach offers great flexibility in choosing an adequate modelling language, once a project has been started it is difficult to change the language itself without invalidating the already designed models. But as models change and evolve in a project, so do metamodels. In this paper we discuss what can be done to transfer models between different versions of a metamodel, thus allowing a simultaneous evolution of models and metamodels. For this purpose, we introduce an unified model for the presentation of models at all meta layers and identify common metamodel refactoring patterns, where model transformations can be derived automatically.