Heuristic for the resolution of the general FMS cyclic scheduling problem

The aim of this paper is to present a new heuristic for the resolution of the general cyclic scheduling problem. This approach consists in determining a cyclic command which respects the hard constant of optimal production speed while minimizing the work in process (WIP). In fact we choose the cyclic behavior to reduce the complexity of the general scheduling problem. In addition we will minimize the WIP to satisfy the economical constraints and the access conflicts to the shared resources of the shop. One of the main interests of our method is to get close to the exact algorithm to solve the cyclic scheduling problem. That's why we consider overlapping cycles, that means that an operation can start in a cycle and end at the next one. The obtained cyclic and deterministic command can be modeled by a Petri net subclass called marked graph and represented by a dual Gantt diagram with both resources and operating sequences points of view.