Product mix optimization for a semiconductor fab: Modeling approaches and decomposition techniques

For optimizing a semiconductor fab we are aiming to match the production capabilities and capacities with the demand in the most profitable way. In this paper we address a linear programming model of the product mix problem considering product dependent demand limits (obligations and demand forecast) and profits while respecting the capacity bounds of the production facility. Since the capacity consumption is highly depended on choosing from different production alternatives we are implicitly solving a static capacity planning problem for each product mix. This kind of planning approach is supported by the fluid flow concept of complete resource pooling in high traffic. We propose a general model that considers a wide range of objectives and we introduce a decomposition heuristic. The computational study of the approaches is based on real world data and on randomly generated instances.