4. Timed Petri nets

4.1 Presentation

The process of designing and implementing a sequential system presupposes a rigorous analysis of the system's functional specifications which, as we have seen, can be based on a model of the "autonomous Petri net" type. In this so-called "validation" stage, the autonomous Petri net, by definition, provides a description of the control part only, a description that is cut off from the environment, and therefore from the operative part, as defined in paragraph 1.4