Analysis of the Impact of Requirement-Sketch Sequencing on Requirement Generation in Conceptual Design

Generally, engineering design progresses from generating requirements to developing concepts. Despite this, educators observe that students have ideas for the eventual solution before fully defining the problem. Thus, a method of exploiting this natural proclivity may result in a better overall product or process. The coevolutionary design may provide a theoretical construct for such a method. Sketching as a first step may improve the resulting requirements, which in turn would result in higher quality solutions. To test this, an experiment is used to study the effects of rearranging the design sequence to use an early conceptual sketch in the elicitation of constraints and criteria. Requirements generated by students were analyzed based on their quantity, completeness, variety, typology, and novelty. It was found that the use of a preliminary conceptual sketch had a significant (positive) effect on the quantity, typology, and novelty of the resulting requirements, 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. Using sketches and feature identification helps in clarifying requirements for the participants. 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 a positive effect.