C3D was assigned by KFKI-RMKI (Research Institute for Particle and Nuclear Physics of the Hungarian Academy of Sciences) to make the integration of the test blanket modul in the first nuclear fusion power reactor. It was not simply the design of a certain product, but that of a whole system (tools and processes). In the second most expensive, and technically the most complex project of the world, C3D has achieved outstanding international success. With the help of Pro/E we could make a remarkably detailed integration concept in a very short time, based on which precise technical parameters could be concluded. At the end of the design process the total time requirement of the complex change procedure (cutting the helium pipe, then welding, ultrasonic scan, and precise positioning of the 100-ton unit) could exactly be determined.