Abstract: From the viewpoint of green manufacturing, energy saving and noise reduction are two important problems that should be considered in machining systems. The task-assigning model of energy saving and the task-assigning model of noise reduction have been studied respectively. But in machining practice, the energy consumption and the noise are coinstan- taneous, and need to be considered together in the task-assign- ing model. A multi-objective task-assigning model is establi- shed so as to consider both energy saving and noise reduction in machining systems. A flexible arithmetic based on genetic algorithm (GA) is also presented to solve the model. Based on the traits of unloaded power and noise of the machine tools, a practical method is developed that simplifies the application of this integrated model. Finally，a case study is analyzed to show that the model and the arithmetic are practically applicable.

Key words: Machining systems Energy reduction, Noise reduction, Green manufacturing