Conceptual design is a high-level cognitive activity that draws upon distinctive human mental abilities. An early and fundamental part of the design process is problem formulation, in which designers determine the structure of the problem space they will later search. Although many tools have been developed to aid the later stages of design, few tools exist that aid designers in the early stages. In this paper, we describe Problem Formulator, an interactive environment that focuses on this stage of the design process. This tool has representations and operations that let designers create, visualize, explore, and reflect on their formulations. Although this process remains entirely under the user's control, these capabilities make the system well positioned to aid the early stages of conceptual design. [DOI: 10.1115/1.4024714] Keywords: problem formulation, conceptual design, design representation, requirement analysis, computer-aided conceptual design
Background and MotivationDesign is one of the most complex cognitive activities in which humans engage, involving sophisticated reasoning about specifications, functional devices, and how the latter satisfy the former. As such, design has long been recognized as standing to benefit from computational aids, and there have been many success stories in the general area of computer-aided design.However, nearly all work in this arena has focused on later stages of the design process, which involve determining the detailed structure of designed artifacts or deciding on specific values for their parameters. In contrast, the earlier, and equally important, stage of conceptual design, or problem formulation, has received relatively little attention. This phase plays a key role in the design enterprise, since it focuses on how one formulates the problem, which in turn constrains the alternatives considered during later stages. Thus, helping users generate promising conceptual designs early on will increase their chances of finding useful detailed designs later.One reason is that design tasks, as typically stated by customers or marketing departments, are incompletely and ambiguously specified. To make them operational, designers must often add requirements, clarify goals, identify trade-offs, and otherwise refine the specifications they have been provided. In other cases, to make the problem solvable they may even need to reject some facets of the specification. These activities occur largely during the conceptual period, although they may well incorporate feedback from later stages, especially when the designer encounters problems that lead him to reconsider earlier choices.There is also reason to believe that the formulation phase is the primary locus of creativity in the design process, particularly for nonroutine problems. Howard [1], in a review of both the design and psychology literature, provides evidence for this claim and identifies conceptual design and task analysis as the phases where the most creative output is produced. Furthermore, Christiaans [2] has discove...