Year of Graduation
Ensuring Сorrect Behavior of Petri Nets by Adding Transition Priorities
System and Software Engineering
In terms of this research paper the problem which is strongly connected to the research area of Petri Nets has been studied and would cover system models with infinitely many reachable states, represented by unbounded Petri nets. Petri nets are widely used for modeling and analysis of all kind of systems ranging from technical systems to systems of business processes. Each Petri net can be characterized by a set of parameters. We’ll focus on two parameters of nets - it is liveness and boundedness. Checking just these two parameters and ensuring if they are true for a net allows to determine, for instance, soundness attribute for a workflow net (a special kind of a Petri net) which is a crucial correctness property for this type of nets. Moreover, the fact that system model is live and bounded, highlights that system is stable and predictable - these two parameters assures system stability in biological systems, also they are welcomed in embedded systems which have limitations in resources. So it is appreciated when one works with bounded and live net, however in real life we can have a net which is live, but is unbounded, i.e. it has an arbitrarily many tokens in at least one of its places. We’d like to find out if it is possible to somehow limit the behavior of such a net to make it bounded, ensuring it is still live. The algorithm introduced and described in article of I. A. Lomazova and L. Popova-Zeugmann, “Controlling Petri Net Behavior using Priorities for Transitions”, offers an approach which allows to overcome the unboundedness by setting priorities to transitions and this way converting a net into a bounded one. This approach will be investigated and realized within this work. Also the paper implies the development of a software tool which would make structural analysis of a net, find transition priorities for a net if they can be calculated, and would visualize the obtained priorities for a given net.