More and more industrial enterprises tend to validate their planning for new factories using simulation. Production environments often contain automated transport systems to move items between different work stations. We present a solution for modeling transport systems with respect to their interaction with all peripheries like robots and treatment machines. Modeling follows the process of mechanical assembly by putting together constructional components in 3-D space. Models of devices are of sufficient physical and electrical accuracy to test unmodified controller programs in a virtual commissioning phase to save time at the real start-up. In emulation, real controllers connect to the model to test and optimize control programs. In contrast to conventional discrete event simulation software, developers can play with the model during simulation to test its reaction and perform event of fault analysis. Simulation results are suited to secure design decisions of planners and reduce the risk of incorrect planning. Easy to recognize 3-D geometry and simulation interactivity qualify models for presentation and personnel training. Finally, simulation reveals suboptimal behavior and makes optimizations easier.