Modal Interface Automata: A Theory for Heterogeneous Specification of Parallel Systems

This thesis presents the latest incarnation of the interface theory of Modal Interface Automata (MIA) which unifies several different types of specification mechanisms. It allows for stepwise and aspect-oriented specifications and provides structural operators, like parallel composition and hiding, logical operators like conjunction and disjunction, and even temporal logic operators like Universal and Existential Next-operators and an Unless-operator. MIA combines the modalities of (disjunctive) Modal Transition Systems (dMTSs) with the input/output handling of Interface Automata (IA). Thus, we examine the fundamentals of these two specification theories considering different aspects of possible refinement relations before presenting the MIA framework. We examine failure semantics and failure/divergence semantics for dMTSs and their justification via testing scenarios. We also examine the fundamental design decisions of IA: the pruning built into parallel composition and the optimistic approach of the refinement. The resulting refinement relations are compared to the more traditional simulation relations on which the refinement of MIA is built. Further insights from these examinations are also incorporated into the interface theory that is MIA