Capacity Planning for Semiconductor Wafer Fabrication with Uncertain Demand and Capacity

Capacity planning, the determination of optimal tools´ configuration based on the current information about future demand and capacity, is very hard due to the high uncertainties in both capacity and demand. To cope with this problem, this paper proposes a scenario-based stochastic programming model to facilitate tool procurement decision-making. The uncertainty of product demand is represented with a set of scenarios with associated occurrence possibilities. And the capacity variability is described with a set of scenarios on tools´ utilization ratios. All of these make the tools procurement plan robust to uncertainties to specific context. The resulting robust tools deals well with the changes in demand and capacity with the maximal expected profits. For those companies of risk-aversion, this model is preferred.