Energy-efficient control of parallel and identical machines: Impact on the overall production system

Nowadays, manufacturing industries are increasing their interest in the energy-efficiency topic, mostly due to the major environmental impact of machining activities. Manufacturing processes sustainability can be improved by controlling machine state with energy-efficient control (EEC) policies that switch off/on the device. Recently, research demonstrated that this approach can be also applied to a workstation composed of parallel and identical machines, switching off/on each of the devices in the workstation. This paper is focused on this type of configuration, analyzing more identical parallel machines workstations belonging to the same industrial production system from the automotive sector. For all of the studied workstations, a proper EEC policy is identified also considering an availability constraint: in this way, the energy consumption is reduced while a target availability level is satisfied for each station. This work aims to show how the EEC of one or more workstations affects the overall production system in terms of throughput and energy consumption. Discrete event simulation is used to perform numerical analysis and, starting from the experimental results, the benefits of the energy-efficient measures on the overall system are presented and discussed.