The main purposes of this paper consist of two parts: Firstly, a simplified equivalent magnetic circuit model of the flux-switching permanent magnet (FSPM) machines is built, which enables demonstrating the relationships between static electromagnetic performances and design parameters, i.e., the parameter sensitivities on performance are to be evaluated. Secondly, a robust design approach for the FSPM machines are presented, which aims to obtain best motor stability and robustness by setting boundaries on design dimensions, when taking into account the manufacturing tolerances.