The submitted presentation focuses on an optimization methodology which uses DoE methods to define component parameters of parallel hybrid powertrains such as number of gears, transmission spread, gear ratios, progression factor, e-motor power, e-motor nominal speed, battery voltage and cell capacity. Target is to find the optimal configuration based on customer targets (fuel consumption, performance targets etc.). In the treated drivetrain configuration, the combustion engine is considered as a fixed component. The introduced methodology reduces development time and increases output quality of the early system definition phase. The output parameters are used as a first hint for subsequently performed detailed component development. The methodology integrates existing software tools like AVL CRUISE and AVL CAMEO [www.avl.com/simulation-solutions]. The new approach in the presented methodology includes specific integrated transmission and e-motor models in the vehicle simulation loop. This enables a calculation of appropriate efficiency maps, based on the defined parameters in every simulation loop. Characteristic parameters of the involved drive train components are delivered by integrated databases and in addition, a battery cell table of available products on the market is linked to the system. Restrictions for design space are technical and physical based, as well as driven by benchmark data. Links between the parameters based on their dependencies to the targets, like maximum vehicle speed, improves the information quality output of the DoE model. To avoid resulting combinations of drivetrain components, which are not able to fulfil the customer targets, a plausibility loop checks and evaluates each combination. In a multidisciplinary optimization process, this procedure avoids results, which include optimum values for one parameter (e.g. fuel consumption), but would lead to disadvantages in other criteria (e.g. performance). Further steps of the project will include a refinement of the system and the implementation of additional drivetrain topologies, like power split hybrid, serial hybrid as well as optimized e-motor design etc. to widen up the usability in system development.