Investigation of Prototype Roles in Conceptual Design using Case Study and Protocol Study Methods

Prototypes play an important role in the engineering design process. Engineering design textbooks often discourage the use of prototypes early in the design process, citing past research on prototypes in engineering design has focused describing and classifying the prototypes themselves. The gap in this research is the investigation of prototyping processes. While researchers have studied the characteristics of different prototypes and in some cases have tried to tie characteristics to the outcomes of the design process, the actual prototyping activities and the process of building and using the prototypes has not been studied in detail. The work presented in this thesis is an initial attempt to explore the the prototyping process in engineering design. Two research studies are presented that have been conducted to explore the roles prototypes fulfill in the early stages of the engineering design process and to study how designers interact with physical objects and prototyping materials. A case study was conducted to investigate the roles that prototypes fulfill in two different industrial settings. To complement this, a protocol study was developed to see how individual designers interact with physical media during a conceptual design activity. The results from these studies were analyzed and it was found that along with the commonly described prototype roles: learning, integration, communication, and demonstration, prototypes can also be classified in terms of divergent or convergent activities; helping designers to either explore a design space or narrow down options and make decisions. Divergent and convergent prototyping activities are presented along with a discussion on how prototypes can be used effectively in conceptual design