A Job Shop Scheduling Problem with Time-defined Re-entrant Process

• Main Authors: Po-jen Hsieh, 謝博仁
• Other Authors: Tsan-Hwan Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/18034808622719356526

碩士 === 國立高雄第一科技大學 === 運籌管理研究所 === 103 === General operation scheduling problems only consider the limitations of process sequences. However, re-entrant process has to be taken care of in some industries. IC assembly and test industry is one of them. The re-entrant process of this industry occurs when the time interval between two consecutive production stages exceeds some pre-defined time limit. This study focuses on the development of a method to solve such a job shop scheduling problem (JSSP) with time-defined re-entrant processes. A mathematical programming model is constructed as basis. Two small- size JSSP instances are used to validate the correctness of the model. Since the job shop scheduling problem with time defined re-entrant process is an NP-Complete problem, it is almost impossible to solve a real-life size instance in reasonable time. A meta-heuristics algorithm based on simulated annealing concept is developed to solve the problem. Since there isn’t any research similar to the problem discussed, two examples from past research are modified by adding hypothetical re-entrant process data. These two modified examples are solved by optimization method and by proposed algorithm, respectively. It can be shown that optimal values found by the algorithm are within 2% errors compared to that from optimization model. However, time required for the solution process from the algorithm is much shorter than that from the optimization. It can thus be concluded that proposed algorithm is a better choice to solve such problems efficiently.