Constant time interval simulation for semiconductor manufacturing

In this paper, we propose an innovative production planning and control methodology, called CONSTIN, and its associated simulation software for large-scale and unstable production environments such as semiconductor manufacturing. CONSTIN presumes to maintain appropriate levels of work-in-process inventory (WIP) and move WIP between processes only at a fixed time interval. Our theoretical analysis shows a clear relationship between WIP levels and the time interval in CONSTIN. Computational experiments using a set of realistic wafer fabrication process data show that CONSTIN simulator is comparable in accuracy to a traditional event-driven simulator and can run much faster than that. Therefore, we conclude that CONSTIN is a promising production planning and control methodology and provides a powerful simulation solution to large scale semiconductor manufacturing processes.