Energy efficiency constitutes a very significant factor that requires its inclusion in the manufacturing decision making attributes developing a strategy to produce more with less. The idle state of a machine tool is an inefficient phase. A strategy to increase the energy efficiency of an already balanced production line, using machine tool stand-by or shut-down modes, during the idle phase, is being introduced. This strategy identifies when the application of such modes is gainful from an energy efficiency point of view, based on the available idle time and the consumption of the machine at these modes.