Evaluation of Design Feedback Modality in Design for Manufacturability

The early conceptual design phase often focuses on functional requirements, with limited consideration of the manufacturing processes needed to turn design engineers' conceptual models into physical products. Increasingly, design and manufacturing engineers no longer work in physical proximity, which has slowed the feedback cycle and increased product lead-time. Design for manufacturability (DFM) techniques have been adopted to overcome this problem and are critical for faster convergence to a manufacturable design. DFM tools give feedback in textual and graphical modalities. However, since information modality may affect interpretability, empirical evidence is needed to understand how manufacturability feedback modalities affect design engineers' work. A user study evaluated how novice design engineers' design performance, workload, confidence, and feedback usability were affected by textual, two-dimensional (2D), and three-dimensional (3D) feedback modalities. Results showed that graphical feedback significantly improved performance and reduced mental workload compared to textual and no feedback. Differences between 3D and 2D feedback were mixed. Three-dimensional was generally better on average, but not significantly so. However, the usability of 3D was significantly higher than 2D. Conversely, providing feedback in textual modality was often no better than not providing feedback. The study will benefit manufacturing industries by demonstrating that early 3D manufacturability feedback improves novice design engineers' performance with less mental workload and streamlines the design process resulting in cost-saving and reduction of product lead-time.