| Several ideation methods are available and used by engineering designers to enable the generation of alternative designs [1]. However, there has been little work done to understand the role that the design problem given to participants plays in the ideation process. The contribution of this research is found through the proposed guidelines with respect to the type of requirements to include as part of the design problem in order to achieve the desired quantity, quality, novelty, and variety of solutions during the early stages of the design process. This work is the first attempt at analyzing the effect of requirement type on the solutions generated to a design problem. A user study is conducted with undergraduate mechanical engineering students to test the hypothesis that functional requirements lead to better understanding of the design problem, and thereby to improved ideation with respect to the quality, quantity, novelty, and variety scores on the solution sets. All the participants were given a burrito folder design problem and asked to generate solutions. The four experimental conditions were functional requirements, non-functional requirements, mixed prioritized requirements, and non-prioritized requirements. This study used a standard set of outcome based measures for ideation: quantity, quality, novelty and variety [1]. The findings reveal that non-functional requirements are useful in ideation to achieve a greater quantity of solution (p-value=0.09) and better quality of solutions (p-value=0.018). It also shows that non-functional requirements positively impact the variety and novelty of solutions. In addition, the mixed requirements groups achieve a better variety than the functional requirements groups. The results highlight potential improvements that might be achieved by using non-functional requirements in ideation. Therefore it is recommended that designers explore these non-functional requirements of a problem, a recommendation that does not align with current best practice design education as seen through a review of popular design engineering text books. These findings lead to areas for future research in understanding how the functionality of requirements influence an engineer's thinking. |
