Real time scheduling of Workflow Management Systems based on a p-time Petri net model with hybrid resources

The objective of this work is to propose an approach based on a p-time Petri net model with hybrid resources to solve the real time scheduling problem of Workflow Management Systems. The proposed approach uses an activity diagram to show the main activities of the system and the different routings of the Workflow Process. Based on the activity diagram, the corresponding p-time Petri net model is produced by assigning a time interval to every Workflow activity. Hybrid resource (discrete + continuous) allocation mechanisms are modeled by an hybrid Petri net with discrete transitions in order to represent the different kinds of resources (equipment and human resources) in a more realistic way. Time constraint propagation mechanisms are presented and a token player algorithm is applied to the Petri net model in order to obtain an acceptable scenario corresponding to a specific sequence of activities which respects the time constraints. The approach is illustrated through an example of “Handle Complaint Process”.