Optimum scheduling of machines and AGVs in a multi-machine FMS with alternative routing using crow search algorithm

This article addresses the machines and automated guided vehicles (AGVs) concurrent scheduling with alternative machines in a multi-machine flexible manufacturing system (FMS) in order to provide the best optimum sequences to minimize the makespan (MKSN). The allocation of AGVs and their related trips, including deadheaded trips and loaded trip times, to job operations (jb-ons), along with the determination of machine selection for jb-ons and the sequencing of jb-ons on the machines, pose significant challenges in solving this problem. The problem is modeled using mixed integer nonlinear programming (MINLP) in this study and solved using the crow search algorithm (CSA). As a means of verification, an industrial problem from a manufacturing company is utilized. The findings indicate that CSA performs better than the existing techniques and that utilizing alternative machines for the operations can bring down the MKSN for 224 minutes and cost $877.