Virtual Petri nets as a modular modeling method for planning and control tasks of FMS

The modeling of automated manufacturing systems has been studied to cope with the production planning and control problems. Petri Nets have been applied to model these systems because they provide resources to represent the systems behavior. When the systems are too large or complex, the modeling task is difficult and the elements in the model are too many for a simple under-standing and analyze task. This work proposes an method for modeling these systems in order to minimize the difficulties mentioned. The proposed method introduces the virtual Petri net (VPN) and a modular strategy considering the shared resources and the alternative process planning. Using this method, a system has been modeled, initially considering the systems elements for the modeling job, and then a modules linking way can be used in order to build the complete model.