Abstract
Overall equipment efficiency (OEE) has been proposed as a comprehensive index for individual equipment performance. However, there are limitations for evaluating only OEE of single machine in semiconductor manufacturing. This study aims to propose overall tool group efficiency (OGE) indices to observe the equipment performance at the tool group level. In addition, rather than evaluating OEE for a fixed period of observation time, we also proposed a mechanism with statistical efficiency control charts to continuously monitor OGE over time. This study constructed a framework for monitoring equipment performances from critical tool groups to single machines via longitudinal analysis. Then, root-cause analysis of machine statuses is employed to identify possible performance detractors. Following the proposed framework, improvement actions can be thus triggered on those critical machine statuses to promote tool group productivity. We used a case study based on real data from a fab in Taiwan for illustration and concluded this study with discussion of future research directions.