Impact of Production Planning Approaches on Wafer Fab Performance During Product Mix Changes

We present the results of a series of simulation experiments examining the impact of product mix changes on global performance measures such as costs and profit. In these experiments, we apply three production planning models in a rolling horizon setting that differ in their anticipation of shop-floor behavior. The first two are based on exogenous, i.e. fixed, workload-independent lead times, while the third uses non-linear clearing functions to represent workload-dependent lead times. The simulation results clearly demonstrate the benefit of production planning models that correctly anticipate the queueing behavior of the wafer fab.