1. Types of application

Two main applications of Petri nets emerge in the literature, depending on whether the net is used during the design cycle or as a system implementation tool. In the first case, the network specifies the system and forms the starting point of the design cycle. These specifications then enable qualitative and quantitative analyses of the system to be designed. Non-compliance with certain clauses in the specifications generates modifications to the model, the repercussions of which are assessed by re-running the analyses. The second category of applications involves using the network as the internal structure of a control or decision support system.