Functional representation as design rationale

The functional representation (FR) framework, which captures the causal component of a design rationale (DR), is described. FR encodes the designer's account of the causal processes in the device that culminate in achieving its function. The representation makes explicit the components' roles in the causal process. The limitations of FR as a design rationale and the limitations of the current repertoire of representational primitives in FR for capturing the causal component are discussed.>