With the availability of cloud-based software, ubiquitous internet and advanced digital modeling capabilities, a new potential has emerged to design physical products with methods previously embraced by the software engineering community. One such example is pair programming, where two coders work together synchronously to develop one piece of code. Pair programming has been shown to lead to higher quality code and designer satisfaction. Cutting-edge collaborative Computer-aided Design (CAD) technology affords the possibility to apply synchronous collaborative access in mechanical design. We test the generalizability of findings from the pair programming literature to the same dyadic configuration of work in CAD, which we call pair CAD. We performed human subject experiments with 60 participants to test three working styles: individuals working by themselves, pairs sharing control of one model instance and input, and pairs able to edit the same model simultaneously from two inputs. We compare the working styles on speed and quality, and propose mechanisms for our observations via interpretation of patterns of communication, satisfaction, and user cursor activity. We find that on a per-person basis, individuals were faster than pairs due to coordination and overhead inefficiencies. We find that pair work, when done with a single shared input, but not in a parallel mode, leads to higher quality models. We conclude that it is not Industry 4.0 technologies alone that influence designer output; choices regarding work process have a major effect on design outcomes, and we can tailor our process to suit project requirements.

Abstract We developed a new method employing automated facial emotion detection software and cursor tracking to link designer emotions and corresponding designer activities while using synchronous collaborative Computer-Aided Design (CAD) software. We applied this method via an experiment with nine participants, each working with the same CAD platform, and assigned a CAD task in one of two distinct working styles: single participants working by themselves and paired participants working together. We analyzed and compared trends in emotion for these two working styles. Pairs experienced, on average per person, higher levels of emotion (measured as joy, sadness, anger, contempt, fear and surprise) than individuals. We linked occurrences of each emotional response to their antecedent activities in the CAD environment (navigating the model tree, sketching, making selections in the feature menu, and communicating). Using a logistic regression analysis, we revealed statistically significant trends linking emotions and antecedent CAD events, and we found that some emotions are more likely to occur with certain designer actions in the CAD software. The method and conclusions presented in this paper allow us to better understand designer emotions in traditional and collaborative CAD, which links to insight related to designer satisfaction, creativity, performance and other outcomes increasingly valued by engineering designers and managers in virtually collaborative environments.

This paper presents the findings of a preliminary study comparing implementation of design changes using various computer-aided design (CAD) working styles. Our study compares individuals’ and pairs’ completion of a series of changes to a toy car CAD model. We discuss the results in terms of productivity and value added ratio, derived from time-based quantitative data. We also discuss qualitative findings acquired through post-study surveys. Overall, our findings suggest that pairs were less efficient than individual designers due to overheads like communication, history dependency and complex couplings within the CAD model tree. However, it is also noteworthy that within each pair the lead participant's performance was at par with individual participants. Lastly, we also discuss behaviors and patterns that emerge as unique to the synchronous collaborative environment, motivating future work.

Serial plates are not reasonable in material saving and stress dispersion. To design orthopedic plates ideally and conveniently, this paper proposes a method to optimize plates through editing semantic parameters based on average bone model. Firstly, for the reasonable distribution of serial plates in number and size, an average bone model is created from the existing bones, among which each bone has a contribution to the average model. Secondly, a common orthopedic plate with semantic parameters is constructed on average bone model and it can be conveniently modified. Lastly, optimizing the thickness of the plate through finite element analysis and genetic algorithm to meet the stress condition and use as little material as possible. The simulation results indicate that the method can save material and disperse the stress of the plates so that it can effectively optimize the orthopedic plates.

Technology is transforming the way engineering designers work and interact with others; Synchronous collaborative computer-aided design (CAD) tools allow designers to manipulate the same model at the same time. We present a new method using automated facial emotion detection software and cursor tracking to map designer emotions and corresponding designer activities in synchronous collaborative CAD. We present findings from a dataset of 9 participants that were assigned to two distinct working styles in the same synchronous CAD environment: single participants working by themselves and paired participants working together. In general, our results show that designers working in the paired workflow exhibited more emotion compared to designers who worked alone. A frequency analysis was performed by linking occurrences of each emotional response to their antecedent activities, revealing that user emotions were predictable to some degree by specific antecedent activities of CAD work. We concluded that activities happening in the graphics area were the most frequent antecedent events of emotions for single-users, while for paired participants, activities in the chat section and feature menu were the most frequent antecedent events for joy and fear, respectively. Finally, logistic regression was applied for each combination of event and emotion for each participant in order to further investigate the relationships between the user activities and emotions, and meta-regression was used to aggregate the regression results for the two different working styles. In particular, for single-users, activities in the model tree were found to be positively correlated to joy and negatively correlated to disgust, and navigating the feature menu increased the likelihood of contempt. For participants in pairs, communicating with CAD partner and receiving communications from partner was associated with joy, navigating the feature menu was associated with sadness, anger and disgust were associated with partner’s action in the model tree, and contempt corresponded to the designer’s own activities in the model tree area. The approach and conclusions presented in this paper allow us to better understand designer emotions in fully synchronous CAD, which leads to insight related to designer satisfaction, creativity, performance and other outcomes valued by engineering designers in a virtual collaborative environment.