1997 Volume 30 Issue 2 Pages 260-267
Due to the processing time variability in batch processes, establishment of a scheduling system to generate robust schedules which have appropriate robustness and good production performance is required. In this paper, a fuzzy-set-based method to evaluate the robustness and detect the bottleneck of the schedule is proposed for this scheduling system. Because of the processing time variations and the interaction among tasks, several policies are investigated to calculate the task starting time by using fuzzy processing time. Then, a robustness measure in accordance with the degree of constraint satisfaction is developed. Since the proposed evaluation method enables explicit treatment of the robustness characteristics of current schedule, bottleneck and robustness distribution can also be obtained successfully. The effectiveness of the proposed method is demonstrated by experiments with a multiproduct process model.
