A framework for the rigorous design of highly adaptive timed systems

Abstract

Adaptive systems can be regarded as a set of static programs and transitions between these programs. These transitions allow the system to adapt its behaviour in response to unexpected changes in its environment. Modelling highly dynamic systems is cumbersome, as these may go through a large number of adaptations. Moreover, often they must also satisfy real-time requirements whereas adaptations may not complete instantaneously. In this paper, we propose to model highly adaptive systems as dynamic real-time software product lines, where software products are able to change their features at runtime. Adaptive features allow one to design systems equipped with runtime reconfiguration capabilities and to model changes in their environment, such has failure modes. We define Featured Timed Game Automata, a formalism that combines adaptive features with discrete and real-time behaviour. We also propose a novel logic to express real-time requirements on adaptive systems, as well as algorithms to check a system against them. We implemented our method as part of PyECDAR, a model checker for timed systems.