Cell scheduling; Group scheduling; Scheduling; Cellular manufacturing; Group technology
Scheduling problem in a cellular manufacturing environment is treated as group scheduling problem, which assumes that all parts in a part family are processed in the same cell and no inter-cellular transfer is needed. In a typical CMS environment, however, there could be some exceptional parts, which need to visit machines in the other cells. This fact limits the applicability of group scheduling approaches. This paper addresses the scheduling of manufacturing cells in which parts may need to visit different cells. A two-stage heuristic named as SVS-algorithm is proposed to solve this problem. These stages are termed as intra-cell scheduling and inter-cell scheduling. Through intra-cell scheduling, the sequence of parts within manufacturing cells is determined. In inter-cell scheduling however, the sequence of cells is obtained. The performance of proposed SVS-algorithm is evaluated on 15 problems selected from literature. The results reveal that the SVS-algorithm performs better than LN–PT method in all the selected problems with respect to average makespan.