Using simulation-based scheduling to maximize demand fulfillment in a semiconductor assembly facility

Abstract

We describe how a large number of products are scheduled to run in parallel on a pool of wire-bond machines to meet weekly demand. We seek to maximize demand fulfillment subject to system constraints. The schedule is generated by a simulation engine and used to control the machines at execution time and also to plan for the start of material. By using online data for equipment status and WIP availability, the schedule adapts to "unforeseen" changes on the shop floor after a simulation run. The frequently updated schedule redirects the line towards maximum demand fulfillment based on the latest status of the line.