The form-affordance-function (FAF) triangle of design

For centuries, the relationship between form and function has been a point of debate in the communities of architecture and design, leading to the development of various theories which have attempted to establish a tangible relationship between these two entities. Besides, the concept of affordance, adopted from Gibson's ecological psychology theory, has appeared as a widely-used concept in design practice and research. Nevertheless, while it is generally accepted that these concepts have close dependencies and interactions, it appears that there is no explicit theoretical framework that relates three of the most fundamental concepts of design, namely form, function, and affordance. This paper aims to analyze the concept of affordance in the context of industrial design, where we attempt to develop insights into the role of affordances in relation to form and function. To this end, we define the form-affordance-function (FAF) triangle of design as a major contributor to the establishment of a partial product design specification (PDS) in the design process. We present several examples to investigate the position of affordances in competition with other design considerations such as engineering performance, ergonomics, and aesthetics. The insights into these relationships could have potential implications for designers in making informed early-stage design decisions.