Fuzzy approaches for robust job shop rescheduling

This paper considers a complex real world job shop rescheduling problem, in which jobs with different levels of urgency arrive every day in the shop floor and they need to be integrated in the existent schedule. A fuzzy scheduling system is responsible for inserting idle times on machines in order to produce initial robust schedules; and a rescheduling system which uses match-up approaches accommodates the newly arriving jobs. The main goal is to investigate the performance of this combined system when the arriving jobs are either rush orders or regular ones. Our results and statistical analysis show that a robust initial schedule combined with match-up rescheduling lead to higher quality and more reliable schedules even when jobs with different urgency levels arrive in a dynamic and uncertain shop floor.