Controlling Petri Net Behavior Using Priorities for Transitions

In this paper we examine how it is possible to control Petri net behavior with the help of time constraints. Controlling here means to force a process to behave in a desirable way by ascribing priorities to transitions and hence transforming a classic Petri net into a Priority Petri net. Liveness and boundedness are crucial properties in many application areas, e.g. workflow modeling and bioinformatics. The main correctness property for workflow models is soundness, which can be reduced to the liveness and boundedness of a modified net. In biological models, liveness and boundedness are important for system stability. The problem of transforming a given live, but unbounded Petri net into a live and bounded one by adding priority constraints is studied in this paper. We specify necessary conditions for the solvability of this problem and present a method for ascribing priorities to net transitions in such a way that the resulting net becomes bounded while staying live.