The prototyping fungibility framework

Prototyping is an indispensable activity in product development that facilitates the generation of knowledge in the design process. It is crucial that this knowledge is the right knowledge (e.g., type, fidelity, and accessibility) to ensure stakeholders can evaluate and decision-make effectively. While this is well-recognised, prior work has focused on classifying prototyping/prototypes by their attributes rather than the knowledge they generate. As prototyping methods have a significant impact on the knowledge generated, both in the activity and resulting prototype, a means by which methods can be classified against knowledge generated would enable support of prototyping method selection, equivalence, and substitution. To this end, this paper presents the existing concept of fungibility - a context-specific value judgement as to whether two 'objects' are the same, and therefore capable of mutual substitution - and considers it in the context of prototyping and knowledge generation. In so doing, the paper provides a framework by which prototyping processes may be compared against their knowledge contributions to determine if they are fungible. This is then shown to support prototyping method comparison, selection and direction. After defining the fungibility framework, value is demonstrated via an illustrative example where it has been applied to the comparison of two prototyping instances. The framework is then appraised for its utility and limitations.