FMS job-shop scheduling under disruptions with consideration of time and sequence deviation

Abstract

In this paper, we present a two-stage procedure off-line scheduling algorithm based on the Lagrangian relaxation method to maintain minimum mean weighted flow time for solving FMS job shop problems. On the other hand, uncertainties in the production environment inevitably result in deviations from the initial schedules. Five types of disruptions are considered in the case of rescheduling with an objective of maximum stability. Regarding the stability (time and sequence deviation) and efficiency (makespan), the simulation results of both short time and long time machine breakdown are illustrated for discussion.