The fact that customers can be a major source of innovation is well known. Research traditions on user-driven innovation have received a lot of attention since the first - search attempts in the early 80s. With today's trend of opening up the internal inno- tion process, innovation actors are no longer restricted to R&D or cross-functional internal teams but include external partners as well. Open innovation and open R&D models are means to manage the increased technological complexity and customer - mands in the global market place. The roles of customers are no longer restricted to p- sive consumers whose latent requirements need to be identified. Instead they have become an active and important part of the innovation process. Von Hippel's 'Democ- tizing innovation' is today's mantra, but how are we to integrate customers in the in- vation process and how can such a process be managed? Patricia Sandmeier analyzes how companies can establish a continuing transfer of c- tomer knowledge to the innovator. She draws on more than 22 European companies and her analytical framework for the case analysis is based on the rather new approach of Extreme Programming (XP) in the software industry. While this approach and the - derlying agile project management practices have received a high acceptance among software engineers, the concept is less known in the 'hardware world' of new product creation.