Electro-hydraulic systems combine the advantages of both, the electromagnetic and hydraulic domain and bring together e.g. the good controllability and precision of electrical drives as well as the unbeatable power density and higher robustness of hydraulics. An interesting application in this area is an electro-hydraulic actuator specifically designed for high-speed, high-force, high-precision punching applications. To further optimize the actuator design for the next machine generation the traditional layout process can be enhanced by an optimization step. This starts at the stage of conceptual design, needs a fundamental understanding of the underlying processes and a multi-domain mechatronic model. Therefore the simulation software designed for optimizing electrical machines is enhanced to cover electro-hydraulic and thermal issues too. The advantages of the integrated approach and the principle functionality of the simulation tool are demonstrated in context of the optimization of a newly developed electro-hydraulic actuator which was originally developed for punching machines.