In Product Service Systems development, understanding the customer use of goods is vital, since the product per se is not sold but rather the performance it brings to the purchaser in terms of added value. Moving away from offering just a product or service to become a provider of "integrated solutions" implies inevitable changes in the interaction with the customer as well as in the way knowledge is managed and shared in the cross company environment. The main aim of this paper is, on one hand, to provide examples of how Product-Service Systems raise the demand on such cross-functional knowledge sharing; on the other hand it aims to point out a set of requirements for the successful development of Knowledge Enabled Engineering systems able to support a PSS paradigm in a Virtual Enterprise context.