Cost Soundness for Priced Resource-Constrained Workflow Nets

摘要

We extend workflow Petri nets (wf-nets) with discrete prices, by associating a price to the execution of a transition and, more importantly, to the storage of tokens. We first define the soundness problem for priced wf-nets, that of deciding whether the workflow can always terminate properly, where in the priced setting "properly" also means that the execution does not cost more than a given threshold. Then, we study soundness of resource-constrained workflow nets (rcwf-nets), an extension of wf-nets for the modeling of concurrent executions of a workflow, sharing some global resources. We develop a framework in which to study soundness for priced rcwf-nets, that is parametric on the cost model. Then, that framework is instantiated, obtaining the cases in which the sum, the maximum, the average and the discounted sum of the prices of each all instances are considered. We study the relations between these properties, together with their decidability.