A formal semantics for Sequence Diagrams and a strategy for system analysis

We propose a semantics for Sequence Diagrams based on the COMPASS Modelling Language (CML): a formal specification language to model systems of systems. A distinguishing feature of our semantics is that it is defined as part of a larger effort to define the semantics of several diagrams of SysML, a UML profile for systems engineering. We have defined a fairly comprehensive semantics for Sequence Diagrams, which comprises sequential and parallel constructors, loops, breaks, alternatives, synchronous and asynchronous messages. We illustrate our semantics with a scenario of a case study of a system of systems. We also discuss an analysis strategy which involves an integrated view of several diagrams.