Companies in high-wage countries are forced to produce highly efficiently to generator profits and to keep their production inland. In order to ensure such a high level of efficiency in production, the input resources must be optimally utilized. This means, that the downtime of machines must be kept as short as possible. The goal of this diploma thesis is to reduce the product changeover time without increasing the central use on a production line for the production of plastic parts. Various Lean methods and tools are used to achieve this goal. Autoneum Switzerland AG, which produces products for various well-known automotive manufacturers, serves as an example. The actual state is determined with a SMED workshop. In the course of this process, the currently required activities and associated times for executing the product change are recorded and tabulated. In order to visualize the necessary routes for a product change, a spaghetti diagram is produced. This shows that many distances are expired several times and the distances are unnecessarily long. A total distance of 818 meters is collected when recording the data. Starting out from the actual state, a concept is developed using Lean methods and tools, which systematically reduces the product changeover time. Methods such as "Single-Minute Exchange of Die" or "5S" are used. By applying these methods, a clearly defined set-up sequence is worked out and the running distances are shortened to the minimum. In addition, a visualization of the preparatory activities is prepared and possible technical improvements are examined. Within the scope of the diploma thesis, not only the primary product changeover is optimized, but also the organizational interfaces are illuminated. The resulting optimizations are then tested in practice in order to ensure their feasibility. By applying the methods and tools described in this diploma thesis, the objective is achieved by reducing the product changeover time from 71 to 45 minutes. This represents a 37% reduction in the product changeover time. Furthermore, by shortening the walking distances to prepare from 818 to 378 meters, a time saving of 6 minutes is realized. Thus, 53.8% of travel distance is saved. To ensure a continuous improvement of the processes, a shopfloor-system is implemented at production line level.