화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.39, No.11, 4203-4214, 2000
Scheduling a single-product reentrant process with uniform processing times
Most semiconductor manufacturing involves multiple stages of batch/semicontinuous physicochemical operations. Scheduling of such plants becomes complex because of a high degree of reentrancy in their process flows, as different lots/batches as well as different tasks of the same lot compete for time on the various processing units at each stage. Scheduling of a single-product reentrant process with uniform processing times is addressed in this paper. First,an analysis of the minimum possible cycle time in such a process is presented. Then, a one-pass heuristic algorithm using a novel priority-based resource-sharing policy is developed. The algorithm is also used to study the impact of the lot release interval on system performance. In comparison to a previous algorithm, the proposed algorithm is much more efficient and gives much better results; thus, it is well suited for a large-scale operation.