Advanced Production Scheduling in a Seagate Technology Wafer Fab

摘要

This work focuses on the highly complicated scheduling problem in wafer fabs. We first provide insights on the broader impact of high quality scheduling decisions in semiconductor industries, and then we discuss traditional heuristic-based scheduling practices versus our mathematical optimization approach. The comparison between our hybrid-optimization scheduling tool against the current simulation scheduler at Seagate shows significant improvements in performance through a benchmark study that involves nine historical datasets of the metrology toolsets in Seagate Springtown. On average, our schedules report: a significant reduction of more than 43% in cycle times for high-priority wafers, a reduction of about 9% in total cycle times, and a 7% increase in throughput; compared to SimModel schedules. The large improvements on these schedule metrics are mainly due to the more balanced allocation of wafers to machines, and the better batching formations that exploit effectively wafers’ release dates and priorities.