Using Petri Nets and Objects: A Formal yet Expressive Approach

Abstract

Petri nets are a formalism well suited for modelling the behaviour of concurrent systems, thanks to many valuable features such as a graphical representation, the possibility to reason about both the states and the operations, a well-defined semantics allowing formal analysis, and the possibility to make simulation or to generate code. However, the expressive power of Petri nets makes difficult the precise modelling of large systems, because of the lack of concepts for dealing with the structure of systems and with their data processing dimension. Thus, there is a need to improve the expressive power of Petri nets, and introducing concepts from the Object-Oriented approach can do this. Object-Orientation and Petri nets complement very well since the former provides efficient concepts to cope with the global organisation of systems and with their data processing aspects, while the latter provides efficient concepts to cope with their behaviour. Throughout this chapter, Petri net refers to High-Level Petri Net formalisms such as [3,6,8,9,1] allowing to handle tokens which may be identified, and more precisely to the Petri Net with Objects formalism [9,11].