Performances evaluation and Petri nets

Petri nets have become a tremendously important mathematical and graphical tool in modeling and performance evaluation of real systems with discrete events that are characterized as being concurrent, synchronous, asynchronous, distributed, parallel, nondeterministic, and stochastic, such as computer systems, communication networks and production systems, etc. Thus, this chapter is a tutorial on Petri nets. However, the goal of this work is not only to introduce the fundamental concepts of Petri nets to the researchers and practitioners who are interested in working in this area, but also to show how this tool has currently advanced in order to be convenient for modeling and analyzing the performances of complex systems involved in many various areas of computer science and other disciplines. Therefore, the chapter first defines briefly the fundamental concepts of modeling and performance evaluation of systems with their link to Petri nets, and afterwards largely describes the fundamental concepts of Petri nets, from their applications, ordinary Petri nets (graphical representation and formal definition), stochastic Petri nets (SPNs), generalized stochastic Petri nets (GSPNs), colored Petri nets (CPNs), to the stochastic well-formed Petri Nets (SWNs) which offer a high-level modeling.