Minimization of makespan without tool delay in a multi machine fms using crow search algorithm

This paper addresses the concurrent scheduling of machines, tools, and automated guided vehicles (AGVs), within a multi-machine flexible manufacturing system (FMS). It aims to minimize makespan (MKSN) by utilizing fewer copies of each tool category, while accounting for transport times across machines to avoid tool delays. Many machines share a central tool magazine (CTM) for storing tools. AGVs and tool transporters (TT) move jobs and tools between machines. The parallel scheduling problem is inherently complex, as it requires computing the minimum number of tool copies for each type, allocating tool copies and AGVs to job operations (jb-opns), sequencing jb-opns on machines, and managing associated trip operations, including both empty and loaded AGV trip times. This study proposes a crow search algorithm (CSA) based on crow's intelligence and a nonlinear mixed integer programming (MIP) framework to represent and solve the concurrent scheduling problem. An industrial problem at a manufacturing firm is used to verify the process. The findings indicate that using an extra copy for one tool category along with a copy for each subsequent tool type, would avoid tool delay and reduce MKSN, and CSA surpassing the performance of the Symbiotic Organisms Search Algorithm (SOSA).