The term ideal machine refers to a hypothetical mechanical system in which energy and power are not lost or dissipated through friction, deformation, wear, or other inefficiencies. Ideal machines have the theoretical maximum performance, and therefore are used as a baseline for evaluating the performance of real machine systems. The term ideal machine refers to a hypothetical mechanical system in which energy and power are not lost or dissipated through friction, deformation, wear, or other inefficiencies. Ideal machines have the theoretical maximum performance, and therefore are used as a baseline for evaluating the performance of real machine systems. A simple machine, such as a lever, pulley, or gear train, is 'ideal' if the power input is equal to the power output of the device, which means there are no losses. In this case, the mechanical efficiency is 100%.