Queueing Model Improves IBM's Semiconductor Capacity and Lead-Time Management

At IBM's 300 mm semiconductor plant in East Fishkill, New York, we developed and implemented the Enterprise Production Planning and Optimization System (EPOS), an advanced queueing network model for capacity planning. EPOS extends earlier queueing network models by adding the ability to model product-specific batch service and batch arrivals and multichamber process equipment, and by embedding a linear program for allocating lots to the right queues when route choices are present. EPOS addresses both short-term tactical capacity planning and long-term strategic capital investment planning. It has become an integral part of predicting factory bottlenecks, prioritizing continuous-improvement efforts, planning capital equipment investments, and managing factory lead times. EPOS results have guided IBM's efforts to improve factory performance and reduce tens of millions of dollars of expense.