From Conditional Specifications to Interaction Charts A Journey from Formal to Visual Means to Model Behaviour

Abstract. In this paper, addressing the classical problem of modelling the behaviour of a system, we present a paradigmatic journey from purely formal and textual techniques to derived visual notations, with a further attention first to code generation and finally to the incorporation into a standard notation such as the UML. We show how starting from Casl positive conditional specifications with initial semantics of labelled transition systems, we can devise a new visual paradigm, the interaction charts, which are diagrams able to express both reactive and proactive/autonomous behaviour. Then, we introduce the executable interaction charts, which are interaction charts with a special semantics, by which we try to ease the passage to code generation. Finally, we present the interaction machines, which are essentially executable interaction charts in a notation that can be easily incorporated, as an extension, into the UML