Performance Analysis of Lot Release and Dispatching Decisions in Wafer Fabrication

摘要

Controlling semiconductor wafer fabrications (wafer fabs) is a difficult task because the water fabs have several distinct characteristics such as a large number of processes involved, long lead time, and re-entrant product flow. Typical operational control issues in the wafer fabs include job releasing, dispatching and batch loading decisions. Most of the research works on operational control problems in the fab studied so far address these control problems separately. This paper is motivated by the belief that an operational control decision affects the performance of the other control decisions, and the existence of bottleneck machines is a core factor for this mutual influence of the control schemes. To examine the impact of the control rules on the system-wide performance, we present bottleneck machine-focused control rules and construct simulation models where these control rules are incorporated. Through simulation studies, the performance of the presented control policies is evaluated, and some insights on the performance of the control policies and their interactions are discussed.