Performance modelling of a flexible job shop by simulation and rerouting

Abstract

The present research work focuses on the simulation modelling of a flexible job shop in order to improve its performance. The performance enhancement of a flexible job shop is carried out by reducing the effect of uncertainties with routing flexibility. Hence, a rerouting methodology has been proposed and it is used in the modelling of a flexible manufacturing job shop. The effectiveness of the rerouting methodology has been analysed by comparing it with other existing rerouting approaches such as all rerouting, queue rerouting, arrival rerouting, and one benchmarking approach, i.e., no rerouting. Mean flow time has been considered as a performance measure to evaluate the methodologies performance. These rerouting approaches are based on rerouting the jobs to their alternative machines when their primary machine fails. Further, simulation studies using ProModel® simulation software have been carried out at different breakdown levels, mean time to repair levels, and utilisation level. Simulation results indicate that the proposed rerouting methodology approach is better than other existing rerouting approaches as it improves 59.28%, 58.62%, 52.18%, and 29.79% of mean flow time compared with no rerouting, queue rerouting, arrival rerouting, and all rerouting approaches respectively.