Model based verification of dynamically evolvable service oriented systems

Dynamic evolution is highly desirable for service oriented systems in open environments. For the evolution to be trusted, it is crucial to keep the process consistent with the specification. In this paper, we study two kinds of evolution scenarios and propose a novel verification approach based on hierarchical timed automata to model check the underlying consistency with the specification. It examines the procedures before, during and after the evolution process, respectively and can support the direct modeling of temporal aspects, as well as the hierarchical decomposition of software structures. Probabilities are introduced to model the uncertainty char- acterized in open environments and thus can support the verification of parameter-level evolution. We present a flattening algorithm to facilitate automated verification using the mainstream timed automata based model checker -UPPAAL （integrated with UPPAAL-SMC）. We also provide a motivating example with performance evaluation that complements the discussion and demonstrates the feasibility of our approach.