This paper describes an approach to the design of brushless dc motors considering cogging torque reduction and running torque optimization to enhance the product robustness. The approach is based on the Taguchi method and utilizes the orthogonal array for design of ''experiments', i.e. the scheme for numerical simulations using a finite element method. The concept of signal-to-noise (S/N) ratio is applied to evaluate the motor performance. A comparison is made between the robust solution and the result obtained using a conventional optimization procedure to demonstrate the effectiveness of the robust design approach.