Assistance System for OCL Constraints Adaptation during Metamodel Evolution

Metamodels evolve over time, as well as other artifacts. In most cases, this evolution is performed manually by stepwise adaptation. In most cases, metamodels are described using the MOF language. Often OCL constraints are added to metamodels in order to ensure consistency of their instances (models). However, during metamodel evolution these constraints are omitted or manually rewritten, which is time consuming and error prone. We propose a tool to help the designer to make a decision on the constraints attached to a metamodel during its evolution. Thus, the tool highlights the constraints that should disappear after evolution and makes suggestions for those which need adaptation to remain consistent. For the latter case, we formally describe how the OCL constraints have to be transformed to preserve their syntactical correctness. Our adaptation rules are defined using QVT which is the OMG standard language for specifying model-to-model transformations.