Mechatronic products are widely spread today, but their development still is a challenge. In addition, with the trend of individualisation, not only one solution must be designed but multiple configurations are needed to fulfil customer-specific requirements. To reduce cost and development time, usually existing products are adapted for this purpose. Even though a lot of knowledge is already available through the previous product version, because of multiple disciplines that must be considered in mechatronic systems, even redesign processes are complex. To support the adaption of mechatronic products to changed requirements, an approach to systematically reuse the knowledge available from previous product versions is proposed in this contribution. Through multidisciplinary behaviour optimisation, the solution space is reduced to build an adapted product meeting the new requirements. The approach is explained in detail and illustrated with the example of an electric window regulator and the results are discussed thoroughly.