Analysing Design Decisions from a Product and Process Perspective

Abstract

Most approaches to integrated product and process design focus on decision support — providing designers with information about the implications of their choices for different stages of the product life cycle. When the needs of different life cycle stages conflict, however, these techniques provide no basis for determining which should take precedence. This paper proposes a methodology for helping designers assess trade-offs between the competing needs to minimize cost and maximize quality, by drawing on principles from decision analysis. Research on decision analysis in design tends to focus on the mathematics of decision-making, but this methodology takes the view that the value of decision analysis is in the insights, not the numbers, it generates. It is argued that decision analysis should not be a normative tool for making optimal choices, but a framework for systematic discussion of important life cycle issues. This paper discusses the implications of manufacturing for design decisions, and proposes four conditions that a systematic approach to design decision-making should address to take these implications into account. The methodology is described, and illustrated with a case study. The paper ends by discussing the future work needed to validate and refine the methodology.