203 精密板金加工のためのネスティング・スケジューリングの研究 : ディスパッチングルールとローカルサーチの融合によるスケジューリング手法の改良(生産スケジューリング・生産管理(1))

Abstract

In sheet metal processing, reducing the waste of raw materials and managing the suitable production schedule are the important factors for the efficient manufacturing. In order to reduce the waste of sheet metal, the optimal cutting layout is determined by nesting. On the other hand, the manufacturing sequence for all manufacturing processes is decided through scheduling. Nesting and scheduling are affected with each other and there sometimes occur a certain trade-off between them. Therefore, those problems should be considered simultaneously in order to increase the efficiency of entire manufacturing activity. We have proposed the integrated method of nesting and scheduling. We adopted EDD based dispatching rule for scheduling in this method. In the manufacturing activity of sheet metal processing, bending process sometimes become bottleneck. In bending process, all parts are processed individually. On the other hand, in welding and assembling processes those are the post process of bending, some parts are combined and processed simultaneously. In order to create more suitable schedule, the combination of parts at welding and assembling processes should be considered when the operation sequence of bending process is determined. Therefore, in this study, we propose a local search method for improving the initial schedule that is created by using EDD dispatching rule. Finally, we verify the effectiveness of the proposed method through some computational experiments.