There has been rising interest in confronting formal models of design with practical design methods, in order to understand better both and to explore how they can improve each other. In this article, we try to map the Radical Innovation Design (RID) methodology in Gero’s Function-Behavior-Structure (FBS) framework. We encounter difficulties in doing so, and propose new constructs extending the FBS framework to account for some processes in RID. For instance, FBS is extended to describe the early stages of RID, where usages are analyzed to identify the appropriate situations and problems on which to innovate. We present a short practical case study to illustrate the relevance of these concepts. Our findings join those of others who have investigated the use of FBS to illustrate innovative projects, where requirements are unclear. We propose perspectives for future research, notably pursuing this work with the situated FBS framework.