Markov chain based idle status control of stochastic machines for energy saving operation

The idle statuses of machines in a manufacturing system consume large quantity energy but with non-value added activities. The real time control strategy that reduces the idle period energy is becoming challenging goal under the energy efficient manufacturing environment. Considering the bottleneck machine in a serial tandem line, the concept of energy saving window of machine idle status is proposed and its essence is discussed. A stochastic system model based on Markov chain is constructed to estimate the energy saving window when a machine is blocked or starved. The numerical results are given by discrete event simulation, where the control rule is formulated to select the suitable energy saving machine during system running process. The throughput and energy consumption of the system is compared for different energy saving strategy and the efficiency of the method is validated.