Innovation systems can be defined in a variety of ways: they can be national, regional, sectoral, or technological. They all involve the creation, diffusion, and use of knowledge. Systems consist of components, relationships among these, and their characteristics or attributes. The focus of this paper is on the analytical and methodological issues arising from various system concepts. There are three issues that stand out as problematic. First, what is the appropriate level of analysis for the purpose at hand?
This paper is an attempt to take stock of the authors' work. In Section 2, the authors reflect upon the emergence and fairly rapid diffusion of the concept ‘national system of innovation’ as well as related concepts. In Section 3, they describe how the Aalborg-version of the concept evolved by a combination of ideas that moved from production structure towards including all elements and relationships contributing to innovation and competence building.