Reentrant Flow Shop Scheduling Problems in Two-Machine Systems

• Main Authors: Weng, Cheng-Yi, 翁正宜
• Other Authors: Guu Sy-Ming
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/50287990308703072258

碩士 === 元智工學院 === 工業工程學系 === 84 === This research focuses on investigating the reentrant flow shop scheduling problem in two-machine systems. We assume throughout this research that all jobs are different, the buffers' capacities are infinite, and all jobs are ready for processing at the beginning of the processing period. The objective is to minimize the makespan . This problem is strongly NP hard. In this research,we develop a branch and bound method by which we could obtain the optimal schedule more quickly. Furthermore, we develop a heuristic method to deal with the large scale problem. By experimenting, we find the error between the optimal solution and heuristic solution is small. We also compare our heuristic method with the traditional rules of scheduling and discover that our heuristic method has a much better performance. In particular, we consider the situation that every job is identical and each processing time of jobs is the same but could be different in two machines. We find the policy“the job with more processes to be processed should be processed first”could obtain the smallest makespan. Moreover, if the processing time of the two machines are the same, this policy could also extend to the systems in which the number of machines are larger than two.