High Level Petri Nets and rule based systems for discrete event system modelling

This paper is threefold structured: the first part presents High Level Petri Nets, a formalism to specify concurrent and discrete event systems. The definition of High Level Petri Nets is made by specification of both formal syntax and dynamic semantics. To do this, a formal definition of composed data types is made, in a similar way to the structured data types of programming languages. The second part of the paper presents a way for implementing the dynamic semantics of High Level Petri Nets by using a modified version of RETE algorithm. A connection between rule-based systems and High Level Petri Nets is presented, and it is sown that for every Petri net, a rule-based semantic equivalent system exists. Third, a rule based language for systems modelling is described and an example of using High Level Petri Nets for modelling a manufacturing system is presented.