Collaborative design provides creative design solutions and improves product quality as well as enriches participants' knowledge. Nevertheless, design and supply chain integration in product development processes is not a trivial task. The complex scenario of the dynamic extended enterprise triggers research toward the development of an innovative co-design platform to support multidisciplinary workgroups. Starting from the definition of a new design process model, the proposed approach is based on the formalization of the distributed knowledge in terms of interaction rules and representational models.