Integrating simulation based scheduling with MES in a semi-conductor fab

This paper discusses how simulation was used to evaluate and characterize the scheduling issues in a semiconductor fab and the subsequent implementation of an integrated scheduling solution. The scheduling system was integrated with the fab MES and a number of other data sources including an integrated machine standards database, preventative maintenance scheduling and a Kanban stage calculation worksheet. It generates the schedule automatically at intervals throughout the day, 7 days per week and is used directly by the shop floor operators. The solution enables the same data to be used for both scheduling and off-line simulation to provide continuous improvement by refining the simulation rules through "what-if" analysis.