Abstract

In recent years, the technological innovation system (TIS) framework and its ‘functions approach’ has reached widespread diffusion among innovation scholars, especially those interested in sustainability transitions. It has so far been used frequently in studies of emerging sustainable technologies in the energy and transport sectors. This chapter provides some conceptual clarification regarding the functions framework, reviews the empirical findings of previous TIS studies and identifies topics to explore in future research. The review shows that a detailed understanding of the underlying mechanisms of some of the functions (‘entrepreneurial experimentation’, ‘market formation’ and ‘development of positive externalities’) is largely missing. More in-depth, qualitative analyses is therefore needed to identify causal chains of events within TISs. The review also reveals that the functions framework is not easily applicable to pure diffusion contexts, which suggests that the TIS framework should be supplemented by a ‘diffusion system’ framework.