Schedulability analysis of MSC-based system models

Message Sequence Charts (MSCs) are widely used for describing interaction scenarios between the components of a distributed system. Consequently, worst-case response time estimation and schedulability analysis of MSC-based specifications form natural building blocks for designing distributed real-time systems. However, currently there ex-ists a large gap between the timing and quantitative per-formance analysis techniques that exist in the real-time sys-tems literature, and the modeling/specification techniques that are advocated by the formal methods community. As a result, although a number of schedulability analysis tech-niques are known for a variety of task graph-based mod-els, it is not clear if they can be used to effectively analyze standard specification formalisms such as MSCs. In this paper we make an attempt to bridge this gap by proposing a schedulability analysis technique for MSC-based system specifications. We show that compared to existing timing analysis techniques for distributed real-time systems, our proposed analysis gives tighter results, which immediately translate to better system design and improved resource di-mensioning. We illustrate the details of our analysis using a setup from the automotive electronics domain, which con-sist of two real-life application programs (that are naturally modeled using MSCs) running on a platform consisting of multiple electronic control units (ECUs) connected via a FlexRay bus