The paper presents the application of a knowledge based software architecture (KBSA) scheme which has been developed and implemented in order to be used as a tool in the electrical machines design industrial process. The proposed scheme's layers are introduced, considering several impact factors from many points of view (i.e. technical, material, algorithmic, economic etc), as well as their interference. It is evident that the specific engineering design problem poses inherent demand for a knowledge representation framework that could support the entire life cycle: requirements, specification, coding, as well as the software process itself. In this context, the work continues by presenting design results of the implemented KBSA for a certain type of permanent magnet motor currently under research in electric vehicle industry, for an in-wheel electric vehicle (EV) application. The KBSA employs evolutionary algorithms for the systematic optimization and the results reveal the effectiveness of the aforementioned procedure followed.