Evolution of Configuration Models – a Focus on Correctness

Structure-based configuration models describe commonality and variability as well as restrictions within and between components of a product domain. Innovation in the development of products drives the development of new components and adaptation of existing components. As a consequence of evolution, the configuration model has to evolve in parallel with its referants in the world. A side effect of using configuration models for describing different and evolving products in one model is an increasing possibility for errors. Keeping an overview of the hundreds or thousands of configurable components and the increasing number of interrelations and restrictions for combinations of those is hard, if not impossible, without tool support. This paper focuses on how to keep a configuration model correct despite its changes. Change operations implement changes to the configuration model. After applying changes, syntactical correctness of the configuration model is checked with pre-defined invariants. A three-step process is introduced that consists of compiling change operations, propagating changes and validating the model after change propagation.