A Study of Inspection Stations Allocation Problem of Production Systems

• Main Authors: Yung-Hung Chu, 朱育宏
• Other Authors: Hsin Rau
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/03328780848571067748

碩士 === 中原大學 === 工業工程研究所 === 89 === Inspection is good for quality control and cost saving in production systems. It is a great challenge for managers to decide locations of inspection activities. Most of literatures considered multistage serial production systems; however, in the recent decades, reentrant production systems with higher complexity emerge. One of the most important characteristics of reentrant production systems is that the work units would be manufactured layer by layer and mostly each layer processes through the same machines. In this research, two mathematical models are developed to find the optimal inspection policies with the lowest production cost for both multistage serial production systems and reentrant production systems. The models are highly extensible and applicable; with properly modifying the factors, the models can be applied to different production systems. We considered all or none inspection levels for each workstation with two types of inspection errors. There are three possibilities for the treatment of detected nonconforming units: repair, rework and scrap. Units that need to be reworked would be sent back to workstations according to its defect. Because there is a potential allocation of inspection station behind each workstation, as the number of workstations increases, the problem size increases exponentially. In order to save the computation time, a heuristic solution method based on the characteristics of the mathematical model is developed, and it has a better result compared with the optimization method based on the complete enumeration. Keywords: Serial production system, reentrant production system, inspection station allocation