Abstract <p>A software tool is proposed for the design of electromechanical energy converters in the power supply systems of cars and trucks. The software takes account of the influence of technological and design defects on the probability of fault-free operation. The basis of the software includes design algorithms for electrical machines developed by Kopylov and Balagurov and the results of three years of research by a team at Samara State Technical University—in particular, a model for determining the electromagnetic parameters of an electrical machine with stator–rotor misalignment, a tool for generating the spreads of random technological deviations of key components in electrical machines, and a tool (based on the theory of dimensional chains) that permits determination of the stator–rotor misalignment from such random technological deviations. Test results for the proposed software are presented: geometric, electromagnetic, thermal, and reliability parameters are derived for the design of an automobile generator. The probability of fault-free operation of the generator bearings is assessed separately.</p>