This paper deals with Flexible Manufacturing System in the context of the future's industry. The problem under study is the Flexible Job-shop which models various production systems. This study aims at scheduling operations efficiently by considering a power limitation. To this purpose, each operation has a power profile depending on the machine it is assigned to. Furthermore, in industry, machines are often left idle. This practice could lead to loss in the available power for the manufacturing system, especially when a machine requires a lot of power when it is not processing any operation. Hence, it is proposed to address the benefits of switch on/off in the Flexible Job-shop problem with power limitations. A mathematical formulation for this problem is presented in this paper. The results are promising and show that it is possible to schedule efficiently operations with power requirements in a production system.