In: Lectures on Concurrency and Petri Nets: Advances in Petri Nets, pages 789-818. Volume 3098 of Lecture Notes in Computer Science / Jörg Desel, Wolfgang Reisig, Grzegorz Rozenberg (Eds.) --- Springer-Verlag, June 2004.
Abstract: Message Sequence Charts (MSC) have been traditionally used to depict execution scenarios in the early stages of design cycle. MSCs portray inter-object interactions. Synthesizing intra-object executable specifications from an MSC-based description is a non-trivial task. Here we present a model of computation called Communicating Transaction Processes (CTP) based on MSCs from which an executable specification can be extracted in a straightforward manner. Our model describes a network of communicating processes in which the processes interact via common action labels. Each action is a non-atomic interaction described as a guarded choice of MSCs. Thus our model achieves a separation of concerns: the high-level network of processes depicting intra-process computations and control flow, while the common non-atomic communication actions capture inter-process interaction viaMSCs. We show how to extract an ordinary Petri net from a CTP model thereby leading to a standard operational semantics. We also discuss the connection of our formalism to Live Sequence Charts, an extension of MSCs which also has an executable semantics.