This article aims to explore different optimization's paths in order to identify the most efficient one for an optimal design of 3-levels flux barriers synchronous reluctance machines. Indeed, to obtain the best shape of flux barriers, leading to the highest performances, we have to determine the wisest way to problematize the study. The goal is to define: on which operating point the optimization should be performed, which objectives and constraints should be set as guidelines and finally which type of calculation algorithm should be used. Adequate choices within these parameters is the guarantee to reach a well designed machine in a reasonable calculation duration.