Implementing HOTs that Generate Transformations with Two Input Models

Model-driven Engineering (MDE) is a paradigm that promotes the use of models and automatic model transformations to handle complex software developments. Model transformations promise to reduce the effort for manipulating models. However, building transformations themselves is not easy. Higher-order Transformations (HOTs) are a means for automatically building model transformations. Building HOTs is in itself a complex task mainly because there are no standard languages for implementing them, and there are not many HOTs available in the literature to learn from. This situation is even worse when more sophisticated HOTs are required with two input models. We consider a real application to generate transformations for tailoring software process, because the generated transformation needs to have two input models: the organizational process and the project context model. In this paper, we show three different techniques for implementing this HOT and discuss their benefits and limitations.