It is probably safe to say that today it is universally accepted and often common knowledge that cooperation between product development and the market functions is crucial for the ability of companies to develop market oriented products. Likewise, there are some strong indications that well functioning cooperation between production and product development is crucial for the development of products that are efficient to manufacture. However, no satisfactory solutions have yet been found to the issues of integration and cooperation. Although there is a consensus of opinion among companies that the need for cooperation is very great, a number of issues still remain to be solved. It is, for example, not clear on which issues cooperation should take place, nor which functions should be involved, nor yet how this should be done. This paper tries to answer some of these questions.