Some Issues About Petri Net Application to Manufacturing and Process Supervisory Control

After some general considerations concerning modeling issues, the paper concentrates on the fact that places are generally interpreted as logical conditions. There are various kind of logical propositions, some (the resources) are consumed when they are used in the same way tokens are removed from places when transitions are fired. Linear logic has pointed out the fact that resources had to be handled with a restricted set of logical rules and that they could not easily be handled concurrently with classical logic propositions. This can be exploited for developing modeling methods based on Petri nets. Then two cases of combining Petri nets and other formal tools are examined: Petri nets and fuzzy sets and Petri nets and differential algebraic equations. It is shown that it is better to avoid a complex integration of the various approaches in order to keep the analytical capabilities of Petri nets.