INFLUENCE OF CONCEPTUAL SKETCHES ON VARIETY, TYPOLOGY, AND NOVELTY OF ELICITED REQUIREMENTS

摘要

The generally accepted engineering design process involves generating requirements prior to developing concepts. Despite this, educators often observe that student engineers tend to have ideas for the eventual solution even before fully defining the problem. Thus, a method of exploiting this natural proclivity may result in a better overall product or process. Coevolutionary design, in which a problem and its solution are developed interdependently, may provide a theoretical construct for such a method. It may be that allowing for the creation of sketches as a first step may improve the resulting requirements, which in turn would enhance the result. To test this, an experiment was developed to observe the effects of rearranging the design sequence to use an early conceptual sketch in the elicitation of constraints and criteria. Requirements were generated by third-and fourth-year mechanical engineering students and were subsequently analyzed based on their variety, typology, and novelty. It was found that the use of a preliminary conceptual sketch had a significant (positive) effect on the typology and novelty of the resulting requirements (α = 0.05), though no change in their variety was observed. Also, an additional intermediate step of identifying key features in the sketch further influenced requirement characteristics. The findings of this study support the coevolutionary model of design and suggest that the sketching of ideas and the identification of features in advance of listing requirements may be a valid design practice in the future. By creating an initial concept sketch and then distinguishing the important aspects of that sketch, engineers would be able to extract applicable requirements which they find inherent in their initial ideas. Finally, this method can align more naturally with the approach that many students employ in design. Rather than modifying behaviors, this method can exploit student behaviors to positive effect.