After having sought to reduce production costs, economic policies dedicated to SMEs tend to promote cooperation and to become more and more systemic. These sorts of policies refer to different underlying models in which firms and technology play different roles. This paper aims at studying the evolution observed in the implementation of SMEs policies. It rests upon a typology built thanks a twofold opposition. One concerns the target of the public action which can be either individual or collective, whereas the second one refers to the impact supposed to be mechanic and structural on one hand or determined by the reaction that takes place within the firm or the group of firms on the other. We examine thirty years of public action referring to this framework what will lead us to insist mainly upon the new systemic policies that promotes spillover, clusters and other poles of competitiveness. Putting some emphasis on the degree and the nature of the commitment of any individual firm in these networks, we conclude shedding some light on the debated questions surrounding the evaluation of public policies and the best practices to promote.