Comparison and evaluation of lot-to-order matching policies for a semiconductor assembly and test facility

This paper is motivated by the problem of assigning semiconductor fabrication wafer lots to customer orders of various sizes. The goal of this research is to develop a method for deciding, on a given day, which orders to fill and the assignment of available lots to orders. This problem can be formulated as an integer program with a non-linear objective and non-linear constraints. Because of the complexity of this formulation, the problem is decomposed into two integer linear programs and solved in sequence by heuristic methods. In this paper, heuristic solutions are selected for the two subproblems and the performances of these heuristics are analysed in an experimental design using a representative data set. Based on this analysis, it is shown that the greedy heuristics selected perform significantly better than current practice. Finally, future research is discussed.