A review of the types of Innovation System identified in the literature points to different models. Besides the very well-known National, Regional, Local, sectorial, and technological innovation systems, combinations of the previous can be identified, proposing sub-models such as National Open Innovation Systems, Regional Open Innovation System, as well as Regional Sectorial Innovation System. Innovation systems are generally formed by 3 subsystems: Productive, Knowledge and Institutional. The interaction among the actors embedded in these subsystems fosters the development of cooperative and innovative attitudes. The literature settles differences between innovation systems disposing, in situ, policy making players or those being supported by collaborations with supra-territorial institutions. In this case, institutional subsystems are viewed as common regional values and culture promoters and diffusers. Another point is the openness of the innovation systems. Some authors consider this is already included in the IS concept while others reinforce the idea of the need of aperture. The previously mentioned types of Innovation System help explain the performance of different kind of regions. But, what happens in micro-regions that require sectorial, market, technological and geographical openness? What happens if the analyzed territory is sectorially specialized but does not have final clients, universities, research centers or policy makers? Would in that case be possible to consider an innovation system in the region? In order to contrast the ROSIS ?Regional Open Sectorial Innovation System-, a qualitative interview is performed with inner players of a micro-region (productive firms, knowledge actors and socio-political institutions). The found openness is not only productive, but also technological, sectorial and market-oriented one. Apart from inner players, external ones are also interviewed (regional policy researchers, policy makers, etc.) to academically validate the ROSIS model. Combining external and internal views of the region, the existence of the ROSIS can be analyzed from a policy sight. The scope of this research is the conceptualization and modeling of the ROSIS. This proposed Innovation System subtype is tested in a county located in the Basque Country (Spain) which counts with a strong productive specialization in the metal industry. The result of the analysis is the modeling of a multilevel IS considering the productive, sectorial, market, and technological openness to outside players, but also inner openness cooperation with all the existing players of the region, in order to consider all the knowledge diffusion chances.
