The motivation for the presented concepts is the demand for even more powerful and flexible methods to develop complex mechatronical powertrain systems for vehicles and mobile working machines. One of the challenges lies within the setup and networking of different development tools for different system components in the powertrain. This has to ensure an integrated tool chain with an automated model transformation from the early specification phase to the design phase and finally to the integration and validation phase. The focus of the used models in the tool chain is the detailed description of the functional, geometric and physical properties for the mechanical, electrical and information processing powertrain and vehicle components. To master this challenge there are model languages used, which can cover efficiently a certain part oft he powertrain development process. In the system design phase the System Modelling Language (SysML) is used. This notation allows the abstract and domain independent description of the required functionality. Using an automated rule-based transfomation the models are converted from SysML to the model environments MATLAB/ SIMULINK. and Modelica. In these environments the algorithmic development for the control unit functions and the description of the physical properties of the subsystems are done. For the prototype development of control units another model transformation from MATLAB/SIMULINK to ASCET is used to cover additional aspects of hardware integration and real-time behaviour in this environment. In the system integration phase the optimized real prototypes are tested and validated together with virtual powertrain components on different testbed configurations used models derived from the design phase of the development process on scalable real-time platforms. During the validation on lest tracks with the complete prototype vehicle only the fine tuning of control functions and the required legal testing is done. The advantage of the described methods is the mastering of complex system functions of the powertrain using an integrated set of specialized development tools.