Design Decision Making: Adapting Mathematical Paradigms to fit Designers' Actual Needs

Abstract

When designing products, designers follow a process in which they compare complex alternatives and select one for further development. Because of the complexity and uncertainty involved in comparing and ranking design alternatives, and the high cost of making bad decisions, mathematical decision methods have long held much theoretical appeal for use in design decision making. However, designers do not use them in most practical design work. Why does this discrepancy between theory and practice exist? This paper is a follow-on to a study presented by the authors last year assessing the costs and benefits of various mathematically-based decision support tools. This work aims to provide insights into the results of that study by presenting ethnographic observations of designer's decision making processes, a description of how the assumptions of mathematical decision methods are not well matched to designer's needs. However, by understanding these needs better we are several steps closer to being able to create decision support tools that product designers will want to adopt.