A Heuristic method for the Unrealated Parallel Machines Scheduling problem

• Main Authors: Ke-Hung Yu, 游擱鴻
• Other Authors: Ching-Fang Liaw, Ph.D.
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/72285006873605606124

碩士 === 朝陽大學 === 工業工程與管理研究所 === 86 === In this research , we examine the total weighted earliness and tardiness unrelated parallel machine scheduling problem. The problem is known to be NP-hard. A tow-stage heuristic method is presented . In the first stage, the lagrangian relaxation technique is applied to a mixed integer programming for mulation of the problem to compute a lower bound , followed by a simple procedure to generate an initial feasible schedule. The second stage consists of a neighborhood search procedure which is used to improve the initial schedule obtained in the first stage. A large number of randomly geaenated problems are used to evaluate the performance of the proposed method. Computational results show that method performs well. The average percentage deviation from the lower bound is about 12.68%. Moreover , the method performs best when the due date tightness faitor is large and the due date range faitor is small , whereas the method performs worst when the due date tightness faitor is small and the due date range faitor is large.