Integrated scheduling of part and tool in a flexible manufacturing system using modified genetic algorithm

Abstract

Scheduling problems in an FMS have been considered as complex optimization problems whose solution by conventional techniques requires a great deal of efforts and time. In this paper, a simultaneous loading and scheduling of part and tool has been proposed for a flexible manufacturing system which has identical machines and a common tool magazine. All the tools are stored in the common tool magazine, and shared among the different machines through a material handling system. Each tool type is single in number. A modified genetic algorithm (MGA) with three parent crossover and a mutation operator is used to find the optimal solution of the loading and scheduling problem. The MGA uses an algorithm which is based on Giffler and Thompson procedure with a heuristic approach to resolve the job conflict and generate an active feasible schedule. The performance of the proposed algorithm is analyzed by comparing the makespan results with the results existing in literature. It is observed that the MGA yields better results than the algorithms reported so far. Furthermore, efficiency of MGA improves as the problem size increases.