Revisiting Compatibility Of Input-Output Modal Transition Systems

Modern software systems are typically built of components that communicate through their external interfaces. The external behavior of a component can be effectively described using finite state automata-based formalisms. Such component models can then used for varied analyses. For example, interface automata, which model the behavior of components in terms of component states and transitions between them, can be used to check whether the resulting system is compatible. By contrast, partial-behavior modeling formalisms, such as modal transition systems, can be used to capture and then verify properties of sets of prospective component implementations that satisfy an incomplete requirements specification. In this paper, we study how pairwise compatibility should be defined for partial-behavior models. To this end, we describe the limitations of the existing compatibility definitions, propose a set of novel compatibility notions for modal interface automata, and propose efficient, correct, and complete compatibility checking procedures.