In this report we define a formal execution semantics for UML activity diagrams that is appropriate for workflow modelling. Our workflow models express software requirements and therefore assume a perfect implementation. In our semantics, software state changes do not take time. It is based upon the Statemate semantics of statecharts, extended with some transactional properties to deal with data manipulation. Our semantics also deals with real time and with multiple state instances. We first give an informal description of our semantics and then formalise this in terms of labelled transition systems. We compare our semantics with other semantics for UML activity diagrams and workflow modelling by analysing the different choices made in those semantics.
|Name||CTIT Technical Report Series|