FMS scheduling using Petri net modeling and a branch & bound search

An optimum scheduling algorithm for flexible manufacturing systems using Petri net modeling and modified branch and bound search is proposed in this paper. A Petri net modeling of the system is first discussed. Then the scheduling algorithm is developed using a modified branch and bound search. The method uses a Petri net model to generate and search a partial reachability graph, and presents an optimal makespan in terms of a firing sequence of transitions of the Petri net model of the system. A software package based an the Windows environment is described which produces a Petri net model satisfying the production requirement and this is used to obtain an optimum makespan through a modified branch and bound search. The results of several simulations are presented to demonstrate the validity of the proposed algorithm and show some improvement over previous work