The Optimal Capacity of In-process Inventory for Detection and Recovery of System Deadlocks in FMSs

• Main Authors: Yang,Yuan Tzann, 楊原讚
• Other Authors: Yang,Neng Shu;Jiang,Jui Chin
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/53010421145616835594

碩士 === 中原大學 === 工業工程研究所 === 81 === In a manufacturing system that uses a robot as a material handling device, deadlocking is defined as a situation in which continuous part flow is inhibited because of a conflict in part flow direction. Once a system deadlock occurs, not only the machines and parts involved in the deadlock will stop working, the entire manufacturing system also loses its production capability. The presence of system deadlocking is an obstacle in design and real time control of flexible manufacturing systems. In a flexible manufacturing system designed to have in-process storages, deadlocking may be resolved with a detection and recovery procedures. Firstly, the detection system identifies the parts and machines participated in a deadlock. Then the recovery system selects and transfers one of the deadlocking part to a in-process storage, and the rest of parts in the deadlock can proceed to its next machine. Therefore, a system deadlock is resolved with appropriate use of in-process storages. To install in-process storages in a manufacturing syatem helps resolving system deadlock but also increases the costs associated with the extra inventory. Therefore to optimize the capacity of in-process storages is necessary. This research develops a series of simulation experiments to investigate the optimal capacity of in- process storage in a manufacturing system using detection and recovery method to resolve deadlocking. The experimental results show that the maximun capacity of in- process storage in a manufacturing system with M machines is [M/2]- . When the routing of parts in a manufacturing system is complicated, the occurrence of deadlocking is frequent, and the utilization of in-process storages is high.