Constraint-based specification of model transformations

► A declarative specification approach for model transformations is provided, at a higher level of abstraction than rule-based model transformation languages. ► A systematic process for correct-by-construction of implementations from these specifications is provided. ► A set of design patterns for structuring model transformations is provided. ► A set of composition mechanisms to facilitate the evolution of transformations is presented. ► A wide range of case studies are presented, together with formal evaluation of transformations developed using our process.