Application of reconfigurable machine tools in the capacity control of job shop systems

In today's market, demand fluctuation is a big challenge for manufacturers. They have to respond quickly and flexibly to satisfy customers' demands to improve competitiveness. Moreover, it renders the production systems complex and dynamical. In this paper, we use capacity adjustment to deal with the fluctuation in demand. We derive an extended mathematical model of a typical job shop manufacturing system by introducing reconfigurable machine tools (RMTs) to analyse the impact of this new class of machine tools on the dynamic behaviour of the system. To improve the ability of capacity adjustment, we include the operations of RMTs into the classical proportional integral derivative (PID) controller. Simulation results of a four-workstation job shop system demonstrate the proposed method can adjust the capacity effectively and show the potential of RMTs in the context of Industry 4.0.