Automotive applications are mostly designed to low costs. Efforts to reduce noise, increase efficiency and expand duty cycles call for optimised machine designs. Sophisticated machine designs require long FEA computing times for the optimisation process. Combinations of calculation approaches decrease the total computing time and therefore costs significantly. A combined analytical and numerical calculation approach is presented, using analytical means for pre-design to match power requirements (torque, speed, current) and FE calculation for magnetic verification. The method is applied to a six-phase claw-pole alternator design.