Synthesis-based variability control: Correctness by construction

In this paper, we show the power of combining modern synthesis technology with a constraint-oriented approach to variability modeling. This combination guarantees the validity of all the required properties simply by construction: including a new property simply requires adding a corresponding constraint. The synthesis procedure will then automatically take care that all generated variants are property-conform. This fully declarative approach leads to a very agile variability modeling framework, where new product lines guaranteeing new properties can be defined ad hoc and are, due to our synthesis technology, immediately operational. As the underlying constraint language allows fully describing the intended solution space without imposing any overspecification, neither on the structure, nor on the artifacts, our approach may in particular be regarded as a step from the today typical settings with closed-world assumption to one with an open-world assumption. Impact and ease of this method are illustrated along a small case study running on our prototypical framework implementation.