Practical simultaneous scheduling of machines, AGVs, tool transporter and tools in a multi machine FMS using symbiotic organisms search algorithm

This paper addresses machines, automated guided vehicles (AGVs), tool transporter (TT) and tools simultaneous scheduling in a multi-machine flexible manufacturing system (FMS) to minimize makespan (MSN). The transfer times of tools and jobs are considered. Only one copy of each type of tool is made available due to economic restrictions. The tools are stored in a central tool magazine (CTM) that shares with and serves for several machines. Jobs and tools between machines are transferred by AGVs and TT, respectively. This simultaneous scheduling problem is highly complex in nature as it involves job-operations sequencing on machines, assigning AGVs and tools to job-operations and associated trip operations including the times of empty trip and loaded trip of both AGVs and TT. This paper presents nonlinear-mixed integer programming (MIP) formulation to model and symbiotic organisms search (SOS) algorithm based on the symbiotic interaction strategies that organisms use to survive in the ecosystem to solve this simultaneous scheduling problem. The results have been tabulated and analyzed. An industrial problem in a manufacturing company is used for verification and the result obtained by SOS algorithm is compared with other algorithm.