Many companies collaborate in company networks in order to increase the competence available for development and manufacturing of products. These companies need to exchange information during all phases in a product realisation project. This information may be very sensitive, eg in the early concept phases for a new product or very important for the production output in the later phases. The objective of this paper is to investigate opportunities and challenges with IT support for interorganisational complex product realisation for small and medium-sized enterprises (SMEs) in the manufacturing industry. Based on three industrial cases the findings show that there are three types of challenges to manage for SMEs that want to collaborate; (1) strategic collaboration, (2) im-provement collaboration, and (3) operative collaboration. These three types of collaboration are critical in order to improve the way customers are served by SMEs.