抄録
Silicon wafer fabrication processes have long and unexpected production lead-time. This unexpected manner is caused by reentrant process where an wafer production lot is operated by a same manufacturing equipment many times during its total lead-time, that is, more than 30 days. Higher equipment utilization ratio requires decreasing customer services in delivery date promising. This paper proposes a method to make a master schedule by calculating product mix for each production period. More than 200 production steps are grouped into appropriate size for weekly time bucket by considering bottleneck production line. Experimental results show that high utilization ratio and customer services can be provided by the proposes model, and farther algorisms are also required.
