Determining an appropriate number of FOUPs in semiconductor wafer fabrication facilities

In this paper, multiple orders per job type formation and release strategies are described for semiconductor wafer fabrication facilities (wafer fabs). Different orders are grouped into one job because orders of an individual customer very often fill only a portion of a front-opening unified pod (FOUP). A FOUP is assigned to each job and is used to move the job throughout the wafer fab after the job formation. We determine an appropriate number of FOUPs for a given order release rate that will yield acceptable values for on-time delivery performance, cycle time, and throughput via discrete event simulation.