In this paper using combination of two separated ideas the torque ripple of Interior Permanent Magnet Synchronous Motor (IPMSM) is reduced. These two ideas are rotor PM segmented and modifying the rotor structure based on pole-arc ratio of flux barrier optimization. In addition the torque ripple due to the reluctance torque component decreased too. Analysis and simulation results including saturation have been performed using analytical method and Finite Element Method (FEM). The rotor flux barrier configuration of the proposed design is carried out by Response Surface Method (RSM) as optimization technique which is verified by FEM