Fully electric vehicles are rapidly gaining user and market interest worldwide, due to their zero direct emissions, appealing driving experience and fashionable perception. Unfortunately, cost, range and reliability have not reached the desired targets yet. Since consumers are prone to spend money to have a more reliable system, Design-for-Reliability will be a useful tool for the Design of tomorrow’s EVs, justifying part of the increased cost for these products. In this work, a vertical model-based approach to design-for-Reliability of power converters for EVs is presented, paying special attention to thermally-induced aging. The design starts from various driving cycles, properly assembled to describe the vehicle mission, then load profiles for the converters are found and the resulting thermal stress is quantified. The converter life-time can be estimated, taking into account also parameter dispersion, and requirements for the active thermal control of the parts modeled achieved, thus giving practical information to the system designers.