2. Functional extensions of Petri nets

Although Petri nets enable basic mechanisms such as synchronization, choice, competition, appointments, etc. to be modeled simply and graphically, they have proved to be very limiting. Indeed, the simple consumption and creation of resources (tokens) does not allow us to model very complex systems. A number of studies have been carried out to extend the reference Petri net formalism to offer more compact and expressive models. However, it will be necessary to find a compromise between the richness of the model through the addition of extensions and the loss of decidability of certain properties. The following section presents some of these extensions.