Analytic real-time analysis and timed automata: a hybrid method for analyzing embedded real-time systems

This paper advocates a strict compositional and hybrid approach for obtaining key (performance) metrics of embedded systems. At its core the developed methodology abstracts system components by either flow-oriented and purely analytic descriptions or by state-based models in the form of timed automata. The interaction among the heterogeneous components is modeled by streams of discrete activity-triggers. In total this yields a hybrid framework for the compositional analysis of embedded systems. It supplements contemporary techniques for the following reasons: (a) state space explosion as intrinsic to formal verification is limited to the level of isolated components; (b) computed performance metrics such as buffer sizes, delays and utilization rates are not overly pessimistic, because coarse-grained purely analytic models are used for components only which conform to the stateless model of computation. For demonstrating the usefulness of the presented ideas we implemented a corresponding tool-chain and investigated the performance of a two-staged computing system, where one stage exhibits state-dependent behavior only coarsely coverable by a purely analytic and stateless component abstraction.