Requirements models at run-time to support consistent system evolutions

Self-adaptive systems call for run-time management because of the environment uncertainty. In addition users may put forward new needs while the system is in execution possibly in response to environment variations. This means that a self-adaptive system needs to evolve at runtime accordingly to the user and context variations. We propose a context-aware framework that is inspired by the feature engineering perspective, and brings requirements specifications at run time by emphasizing the requirements that are context-dependent. We support system evolution by proposing a notion of correctness which is based on our context requirements. Our framework is generic and it is amenable to augment the system with new requirements arising at run-time. Since new requirements may interact with deployed requirements we provide the support to keep those entities at run-time and check their correctness jointly. Furthermore we identify the characteristics that a requirement language should have, to manage and check requirements at run-time in our framework.