Automata-Based Refinement Checking for Real-Time Systems.

Today's mechatronic systems are increasingly interconnected using communication protocols for realizing advanced functionality. Communication protocols underlie hard real-time constraints and need to meet high quality standards for ensuring the safety of the system. A common approach for achieving their necessary quality and mastering their impending complexity is model-driven development. Applying this approach, a developer builds formal models of the communication protocols and applies formal verification techniques (e.g., model checking) for proving that the communication is safe. However, these techniques typically face the state-explosion problem that prevents proofs for large systems like interconnected mechatronic systems. In previous publications, we introduced the MechatronicUML method that provides a compositional verification approach for tackling the state-explosion problem. A key enabler for such an approach is a definition of refinement. In this paper, we extend the compositional verification approach of MechatronicUML in particular by using different kinds of refinement definitions including an automatic selection of the most suitable refinement definition. In addition, we significantly extend an existing approach of test automata construction for refinement checking. Using this approach we can also guarantee that a refined model is constructed correctly concerning the selected and applied refinement definition. We evaluate our approach by an example of an advanced railway transportation system.