The Side Transformation Pattern: Making Transforms Modular and Re-usable

The basic principles of meta-modelling are now well established for individual models. Activities such as the MOF QVT [QVT-Merge Group, “Revised submission for MOF 2.0 Query/Views/Transformations RFP (ad/2002-04-10)”, OMG Document ad/04-04-01, URL: http://www.omg.org/docs/ad/04-04-01.pdf] are now extending these principles to transformation between models. However, meta-model incompatibilities between transformations reduce opportunities for effective re-use, hindering wide scale adoption. We introduce a pattern, the Side Transformation Pattern, that arises naturally as transformations are made re-usable, and present a series of examples that show how its use can bring clarity and robustness to complex transformation problems.