Abstract
Because of the manufacturing process complexity in semiconductor manufacturing, dispatching has been an important factor to the overall fab productivity and equipment effectiveness. Although there are numerous dispatching methodologies, almost all of them are designed from the production perspective. A great majority of them are based on the optimization of production, cycle time, equipment utilization, bottleneck machines, etc. However, from the business perspective, what counts at the end is the customer side of the story – not the internal manufacturing perspectives. The customer-driven factors such as order hit rate, profit, and customer relationship – for long-term business – are rarely considered in designing the dispatching rules. The very few researches which consider target hit rate used turn ratio to estimate the lot progress in the fab in order to control the lot processing speed. However, pure turn ratio failed to consider the great differences in the actual time needed to progress over various manufacturing stages. Using turn ratio to control the lot progress cannot accurately control the speed of the lot progress.This research attempts to optimize the dispatching integrating customer-driven perspectives – namely target hit rate. This research uses actual process time as the weight to control the target hit rate in order to more accurately control the actual lot progress. This dispatching method was compared to FIFO、GFIFO、CR、EDD、T.R and showed better hit-rate and production result compared to all the other ones.