This paper aims to present the formalization of a decision support for the management of competencies exchanges within networks of firms, based on both qualitative and quantitative models linked to the concept of competence. These models provide a structured and formal definition of the notion of competence. An important originality of this work lies on the attempt to go further than a qualitative methodology, in order to provide a quantitative management of the development of competencies. This issue is further developed in the context of inter-firms cooperation: we propose a regulation mechanism for competencies' exchanges, based on a principle of equity applied to the increase of competencies for each partner within a network. Finally, we apply this study to an industrial case study.