Towards the applicability of alf to model Cyber-Physical Systems

Systems engineers use SysML as a vendor-independent language to model Cyber-Physical Systems. However, SysML does not provide an executable form to define behavior but this is needed to detect critical issues as soon as possible. Action Language for Foundational UML (Alf) integrated with SysML can offer some degree of precision. In this paper, we present an Alf specialization that introduces the synchronous-reactive model of computation to SysML, through definition of not explicitly constrained semantics: timing, concurrency, and inter-object communication. The proposed specialization is well-suited for safety-critical systems because it is deterministic. We study one example already modeled in the literature, to compare these approaches with our one. The initial results show that the proposed specialization helps to couple complexity, provides better composition, and enables deterministic behavior definition.