Engineering designers frequently use prototypes to gather input from stakeholders. Design guidelines recommend the use of quick and simple prototypes early and often in a design process. However, the type and quality of a prototype can influence how stakeholders perceive a new design concept and can therefore impact their responses. Additionally, different levels of experience, expertise, and preparedness for providing input to designers may lead stakeholders from different geographical or cultural settings to provide different responses, making the format of a prototype even more influential. Although design practitioners are known to intentionally align their prototyping approach with the specific design question to be answered, it is unclear the extent to which prototyping approaches should vary based on the stakeholders, context, and setting of a design project. To investigate how the format and quality of prototypes influence stakeholders' responses, we conducted a field study with various medical professionals in Ghana. We presented prototypes for a medical device in different formats to stakeholders and collected responses to the design through semi-structured interviews. We found that professional expertise, prototype format, and question type influenced the types of responses that stakeholders provided. These findings suggest that designers seeking input from stakeholders on new concepts should consider context-specific prototyping strategies, especially when designing at distance and across cultures.

Design decisions often require input from multiple stakeholders or require balancing multiple design requirements. However, leading axiomatic approaches to decision-based design suggest that combining preferences across these elements is virtually guaranteed to result in irrational outcomes. This has led some to conclude that a single "dictator" is required to make design decisions. In contrast, proponents of heuristic approaches observe that aggregate decisions are frequently made in practice, and argue that this widespread usage justifies the value of these heuristics to the engineering design community. This paper demonstrates that these approaches need not be mutually exclusive. Axiomatic approaches can be informed by empirically motivated restrictions on the way that individuals can order their preferences. These restrictions are represented using "anigrafs"-structured relationships between alternatives that are represented using a graph-theoretic formalism. This formalism allows for a computational assessment of the likelihood of irrational outcomes. Simulation results show that even minimal amounts of structure can vastly reduce the likelihood of irrational outcomes at the level of the group, and that slightly stronger restrictions yield probabilities of irrational preferences that never exceed 5%. Next, an empirical case study demonstrates how anigrafs may be extracted from survey data, and a model selection technique is introduced to examine the goodness-of-fit of these anigrafs to preference data. Taken together, these results show how axiomatic consistency can be combined with empirical correspondence to determine the circumstances under which "dictators" are necessary in design decisions.

Design for assembly is the concept of carrying out critical thought early in the design stage to create assembly easement at the production stage. In the aerospace industry, products have very long lives, frequently being optimised rather than introducing new products. This has meant older products, which are stable income generators, have not benefited from the latest design for assembly methods and manufacturing technology suffers from obsolescence. It has been established that a large percentage of overall product cost is determined at the design stage; thus, existing products suffer from preloaded costs. This paper takes existing design for assembly methodologies and analyses them with respect to the unique challenges involved in legacy product redesign. Several novel factors that contribute to redesign analysis are identified such obsolescence impact and a holistic operation difficulty assessment. A tool is developed to identify potential redesign for assembly projects. The tool is demonstrated through the application of real data and comparing against business decisions. The tool was found to provide a strong indication of where profitable projects may be launched.

In some mechanical engineering devices the novelty or inventive step of a patented design relies heavily upon how geometric features contribute to device functions. Communicating the functional interactions between geometric features in existing patented designs may increase a designer's awareness of the prior art and thereby avoid conflict with their emerging design. This paper shows how functional representations of geometry interactions can be developed from patent claims to produce novel semantic graphical and text annotations of patent drawings. The approach provides a quick and accurate means for the designer to understand the patent that is well suited to the designer's natural way of understanding the device. Through several example application cases we show the application of a detailed representation of functional geometry interactions that captures the working principle of familiar mechanical engineering devices described in patents. A computer tool that is being developed to assist the designer to understand prior art is also described.

This paper describes an engineering design methodology, called conceptual design for assembly (CDFA) in the context of aircraft development, to assess aircraft systems' installation during conceptual phase, in relation to industrial performance objectives. The methodology is based on a given framework (hierarchical structure) which includes a set of attributes, collected in recognized domains that characterize the aircraft systems installation. The framework of the CDFA methodology enables to analyze product architectures at different levels of granularity, splitting the global analysis into sub-problems (problem discretization) with the aim to help architects and designers to identify product architecture weaknesses in terms of fit for assembly performances. The CDFA methodology was applied on a complex system (the nose-fuselage of a commercial aircraft) presenting a high number of criticalities both for the product and its assembly operations. Results identified the architectural components leading to the less efficient assembly operations and the rationales enabling to elaborate alternative architectures for an improved product industrial efficiency.

Lower costs and higher employee satisfaction are some of the benefits driving organizations to adopt dispersed and virtual working arrangements. Despite these advantages, product design engineering teams-those who develop physical products-have not widely adopted this working style due to perceived critical dependence on physical facilities and the belief that it is ineffective to communicate technical details virtually. This paper uses the mass shift in working conditions caused by the COVID-19 pandemic to explore the feasibility of virtual and distributed work in product design engineering. We conducted 20 semi-structured interviews with product design engineers working virtually to uncover current challenges of, and the beginning of promising strategies for, effective virtual engineering work. We categorize and analyze Tangible Design activities, Intangible Design activities, and Communication and Project Management activities throughout the product design process. Contrary to present opinions, we found that much of a product design engineer's work is realizable in a virtual and distributed setting. However, there are still many challenges, especially when attempting Tangible Design activities-those that require physical products and tools-from home. These challenges, missing from existing virtual product design engineering literature, include but are not limited to individuals' lessened sense of accountability, fewer de-risking opportunities before product sign-off, and limited supervision of production staff. Product design engineers described novel strategies that emerged organically to mitigate these challenges, such as creating digital alternatives for engineering reviews and sign-offs and leveraging rapid prototyping. Recent advances in technology, an increased commitment to reducing environmental impact, and better work-life balance expectations from new generations of workers will only push society faster towards a distributed working model. Thus, it is critical that we use this opportunity to understand the existing challenges for distributed product design engineers, so that organizations can best prepare and become resilient to future shocks.

Drawing upon Bourdieu's conceptualization of habitus, this ethnographic study explores the cultural bases guiding engineering makerspaces at a public university in the United States. Students carry forms of capital that impact their entry into these learning spaces, over time becoming disciplined in the "game" of makerspaces as they accumulate capital through everyday talk and storytelling. Communication constructs the makerspace habitus as students (1) move from outsider to insider as they acquire forms of capital; (2) negotiate a habitus characterized by tensions of access vs. exclusivity; (3) learn to use the vocabularies of innovation and creativity; and (4) cultivate supportive making communities. Findings point to the critical role of intentional communication and space design in cultivating inclusive makerspace cultures.

The goal of this work is to compare the outcome of a design for additive manufacturing (DfAM) heuristics lesson conducted in a virtual learning environment to the same in an in-person learning environment. Prior work revealed that receiving DfAM heuristics at different points in the design process impacts the quality and novelty of designs produced afterward, but this work may have been limited by the solely virtual format. In this work, an identical experiment was performed in a face-to-face learning environment. Results indicate that neither learning format presents an advantage over the other when it comes to the quality of designs produced during the intervention. Participants across all experimental groups reported an increase in self-efficacy after the intervention, with improved performance on quiz-type questions. However, the novelty and variety of the designs produced by the in-person experimental groups were significantly lower than that of the virtual experimental groups. In addition to validating the effectiveness of virtual instruction as a teaching method, these results also support the authors' hypothesis that the priming effect is stronger in an in-person classroom than in a virtual classroom.

Customer requirements (CRs) are the essential driven forces of product development. Constrained by the rigid budget and time allocated to product development, much attentions and resources should be paid on critical customer requirements (CCRs). Product design occurs with an increasingly frenetic pace of change in today's competitive market, and the changes of external environment will lead to the changes of CRs. Thus, involving the sensitivity of CRs toward influence factors to identify CCRs is of great significance to grasp the directions of product evolution and enhance market competitiveness. To fill this gap, this study proposes a CCRs identification method integrated Kano model and structural equation model (SEM). First, the Kano model is adopted to determine the category of each CR. Second, based on CRs' categorization, an SEM model is established to measure the sensitivity of CRs toward the turbulence of influence factors. Then the importance of each CR is calculated, and by integrating the sensitivity and importance, a four-quadrant diagram is constructed to identify the CCRs. Finally, the identification of CCRs for smartphone is implemented as an example to demonstrate the feasibility and additional value of the proposed method.