Abstract: As we try to develop new 3D-Sketching devices we come across the problem of how to transfer 3D-Sketches into exact product models to gain an integrated design system. There are some promising approaches for the retrieving of 3D-geometries out of 2D-Sketches, but nearly none supports the concretization of 3D-Sketches. We are developing an intelligent assistant that supports the designer in the task of concretization. Our higher level goal is a system that uses a cad-kernel and supports the designer from the early stages of sketching up to the modelling of exact product representations.