An approach of dynamic bottleneck machine dispatching for semiconductor wafer fab

This paper proposed a dynamic bottleneck dispatching (DBD) policy to consider the dynamic bottlenecks for semiconductor wafer fabrication system. The DBD policy adopted the multi-class priority queuing model and developed a procedure to assign lots to different priority classes. Each queuing lot was assigned to a priority class by 3 decision parameters, which could be optimized by the response surface method and a desirability function approach. A case study based on a local fab was described to examine the performance impact of the DBD policy measured by CT, Var CT, WIP, and TP. The results of the simulation experiments and analysis showed that the DBD policy is superior to the use of the static dispatching rules. In future work, the DBD policy could be integrated with manufacturing execution system (MES) for scheduling wafer fab.