This paper presents the non-symmetrical optimum method, which is an analytical approach to the tuning of RID controllers. This method, derived from Kessler’s symmetrical optimum method, is based on the specification of the closed-loop resonant peak, and leads to optimization of the closed-loop performance. Moreover, the NSOM uses an integration plus first-order model, which, for various applications, is more realistic than the usual first-order plus dead-time model. By highlighting the process characteristics that determine the closed-loop behavior, this approach allows one to optimize simultaneously the plant design and the controller tuning. Its efficiency is demonstrated experimentally by the tuning of the current regulated supply of a DC actuator.