Transforming UML sequence diagrams into petri nets

Abstract

Sequence diagrams are an abstraction of communication modeling taking place between different entities, objects or classes. Their usefulness and expressivity lies in their ability to describe an execution trace of a particular system at a particular point in time. From their initial use as traditional message sequence charts to the current versions of sequence diagrams, like those found in the UML, these notations have undergone various changes and improvements. Their major use still relies in their ability to express the inter messaging between different entities. Sequence diagrams are not proper formal notations and these lack particular executable semantics precisely because of their usefulness to different scenarios and levels within the process of systems engineering. Various proposals have been given to formalize and improve these notations. Petri nets are graphical formalisms that support rigorous verification. This paper defines and explains the relationship between sequence diagrams and normal Petri nets. This approach is used to transform sequence diagrams into Petri nets. A case study of a banking application is used to illustrate the concept. Findings are discussed. The concepts can be extended to other variants of sequence diagrams.