Our article proposes a preliminary framework to analyze an organizational model which can support the intermediation work required to bridge design and innovation. After stressing that ergonomics successfully enriches design processes (first circle), we construct a framework to investigate how innovation processes (second circle) can be understood and managed by activity-centred approaches. We refer to: (1) models of innovation (e.g. Open Source Software) to identify organizational rules enhancing the innovation process (e.g. discussion and production rules) and (2) research in socio-technical system innovation, which highlights the roles of intermediaries in innovation processes. We then apply this framework in the French primary sector to analyze four design-innovation processes contributing to agro-ecological and sustainable transitions. Finally, we discuss the differences that our framework allows us to highlight among these four cases, and point out the shortcomings of this framework that need further investigation.