In this paper, we describe the configuration tool Drive Solution Designer (DSD). The DSD is used by sales engineers of the company Lenze AG (www.lenze.com) for the configuration of complex drive systems in order to make on-site offers together with the customer. The aim of this process is to generate a consistent solution which fulfills the functional requirements of the user along with optimization criteria such as price and delivery time. The preparation of a technical offer requires fundamental knowledge of complex physical and in particular technical correlations of drive components, in depth knowledge of the product catalog as well as high empirical knowledge about the order of the parameterization of the components. In order to meet these requirements knowledge-based AI-techniques are required. In the DSD we use a domain independent incremental structure-based configuration approach with different knowledge representation mechanisms and a sophisticated declarative control. Currently DSD is used with great success by approx. 150 sales engineers of the company Lenze for the design layout task. The introduction of the DSD lead to a drastic time reduction for drive solution development and reduces incorrect solutions to nearly 0 percent.