An Emergent Model for Mobility Product Design Partnerships: A Conceptual Framework For Ongoing Stakeholder Participation in Wheeled Mobility Product Design

RESNA 28th Annual Conference - Atlanta, Georgia

R. L. Grubbs, MA, MEd, Randy Bernard, MID


In this paper, we briefly review several methods and approaches that have been recommended and used in technology R&D, tech transfer and commercialization of new and improved AT devices. We identify popular methods and list limitations that each of these methods presents when applied to the design of new wheeled mobility devices. Next, we present an emergent process model we have developed that utilizes design partnerships and on-going stakeholder participation. We conclude with a description of how we use this model in the design of several new, wheeled mobility products.

KEYWORDS: wheeled mobility devices; participatory action research; QFD; product design partnerships; focus groups; survey, tech transfer, emergent model


We are faced with the challenge of improving the tech transfer and commercialization of new, wheeled mobility products. Our Center, The Rehabilitation Engineering Research Center on Wheeled Mobility (MobilityRERC) is located within the Center for Assistive Technology & Environmental Access (CATEA) at Georgia Institute of Technology. The MobilityRERC, like other centers in academic research settings, can bring considerable resources and expertise to bear on technology research and development of new mobility technology. But to achieve the desired impact on the lives of people with disabilities, we must find effective ways to transfer and commercialize these new devices. We must build and maintain what Steve Bauer has describes as effective “academic partnerships” with mobility device manufactures (S. Bauer, personal communication, lecture, CTIA, March 22, 2004). What model, method or set of strategies can be used to accomplish this goal?

Several methods and approaches are being used with varying degrees of success. These include Quality Functional Deployment (QFD), the Customer Ideal Product Program (CIPP), User-Centered Design (UCD) and Participatory Action Research (PAR) methods. We suggest that each of these approaches to stakeholder involvement and product design partnerships contributes to our understanding but also presents limitations in practice. We prefer a pragmatic approach developed and tailored to the company culture of our commercial partner(s) while leveraging our unique expertise and resources.


QFD is a technique or discipline that has been used to improve the process of product design and development. (1) In the Consumer Ideal Product Program, Stone describe how the RERC on Technology Transfer (T2RERC) used QFD to identify the features of an ideal device and then evaluate or benchmark existing products relative to the features of the ideal device . (2) Jacques and colleagues used QFD in the design of a prosthetic hand and describe QFD techniques including the “House of Quality” and “voice of the customer,” as excellent communication strategies that can be used to communicate design information to all groups involved in the product design and development process. (3) Neither Stone nor Jacques developed working “academic partnerships” with manufacturers and used QFD for the design, development and commercialization of new mobility products. They claim that QFD can be an effective tool for building partnerships based on collaboration and communication, but do not provide evidence of academic/commercial partnerships that utilized QFD. It is necessary to understand and work within the partner’s culture and capacity to create a successful academic/commercial partnership.

User centered design (UCD) is a multi-disciplinary activity, that incorporates human factors and ergonomic knowledge and techniques with the objective of enhancing effectiveness and productivity, improving human living and working conditions, and counteracting the adverse effects of use on human health, safety and performance. UCD consists of four core design activities; understanding contexts of use, specifying user and organizational requirements, producing design solutions, and evaluating design solutions against requirements. (4) Vanderheiden and Tobias discuss incorporating UCD in the design of assistive technology devices by encouraging designers to create products that are usable by people with the widest possible range of abilities within the broadest contexts, as is commercially viable. (5) Because UCD principles are primarily created for the design of software interfaces, variance occurs in the application of these principles to the design of other types of products. We are applying UCD principles, but have not found evidence that wheeled mobility product manufacturers recognize their usefulness.

Much the same type of problem appears to exist when applying participatory action research (PAR) methods to product design and development. PAR is a social science research and program evaluation tool that has become increasingly important to disability and rehabilitation research due to the increasing use of qualitative inquiry strategies. PAR places the people being studied at the center of the decision-making process. In PAR, participants must communicate the context of their lives to investigators and investigators must train participants to become co-investigators who can use research tools, processes and data. PAR utilizes a team approach that integrates participants into the research and development process. (6) We are adapting PAR methods and are evaluating their utility in the development of wheeled mobility products.


Graphic 1: CATEA's Emergent Model for Mobility Product Design Partnerships (Click image for larger view)
The graphic is a venn diagram with three interlocking circles. The circles are titled, Technical Factors (feasibility), Business Factors (viability) and Human Factors (usability) respectively. The area where the three circles intersect is shaded and titled, Product System. Arrows point from each circle to the other two, indicating interactions between all three circles in the development of a product system. The circle titled Technical Factors contains the subtext, Production Process, Planning, Manufacturing and Assembly. The circle titled Business Factors contains the subtext, Business Process, Marketing, Product Cost and Market Need. The circle titled Human Factors contains the subtext, Design/Development Process, Research, Design and Engineering.

To address the problems described above, we propose an emergent model for developing and maintaining product design partnerships with wheeled mobility manufacturers and facilitating the ongoing participation of stakeholders. As the diagram below illustrates, CATEA’s Emergent Model for Mobility Product Design Partnerships simultaneously reflects three interrelated elements necessary in the development of new products; human factors, technical factors and business factors. The emergent model depends on industry participation from the outset. The model causes us to focus on the relationships and interactions necessary to build and maintain technology alliances. By incorporating industry participation from the onset, we are gaining important market research, expertise in design, fabrication and distribution, and a manufacturer willing to invest time and resources in the development of a new product. This collaboration strengthens our ability to create useful technology and move it to the marketplace.

As the diagram illustrates, many interactions exist between each set of factors. There are very few times when one factor drives a decision for the project. A successful product design process considers all factors to ensure that the proper solution is reached. If one factor takes precedent over the other two, important design drivers are lost and the product may fail in the market. The most important strategy in the emergent model is flexibility in adapting to the industry partner’s corporate culture and R&D processes. A second important strategy is documenting and evaluating the processes that are utilized. To reflect all factors, product design teams have been created for each product. Each team has representation from all three factors. RERC project personnel and industry partners receive ongoing training in this team approach. While a complete discussion of the emergent model cannot be accomplished in this paper, we provide a brief overview of the factors and interactions and highlight examples of the application of the emergent model to the development of a dynamic seating system for users with high extensor tone, a low-cost durable cushion, an alternating pressure cushion, and wheelchair for frail elders. Each product is being designed and developed with a different commercial partner.


Business factors focus on the commercial viability of a product/system. This area is the exclusive domain of the commercial partner. The commercial partner brings expertise in market analysis, distribution costs, price points and reimbursement issues. These constraints feed into the technical and human factor domains. Wheeled mobility manufacturers will not dedicate resources unless a product idea has the potential for success. Human factors address usability of the product/system. Human factors includes the interaction between the user and the device, the device’s interaction with the environments of use, and the user’s interaction within these environments. Usability begins with a focused needs assessment that addresses the various tradeoffs of features and complexity. Technical factors relate to the feasibility of the design and technical manufacturing issues. It may include the applications of QFD or other engineering and design methods focused on the functionality of the device, including materials science and mechanical and electrical engineering. Because the partner will manufacture the device, it must fit the materials and processes of the partner. We recognize that industry needs and priorities change and we have experienced the dissolution of a partnership. But, we have found that our emergent model allows for a pragmatic approach for developing and maintaining mobility product design partnerships.


This work is part of the Rehabilitation Engineering Research Center on Wheeled Mobility in Everyday Life (MobilityRERC) and is funded by the National Institute on Disability and Rehabilitation Research (NIDRR) Grant # H133E030035.


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  2. Stone, V.I., Bauer, S.M., Lane, J.P., Usiak, D.J., Khan, Z. & Prabhu, C. (1998). Wheelchair tie-downs: ideal features and existing products. Technology and Disability 8, 159-178.
  3. Jacques, G.E., Ryan, S., Naumann, S., Milner, M., & Cleghorn, W.L. (1994). Application of quality function deployment in rehabilitation engineering. IEEE Transactions on Rehabilitation Engineering, 2(3), 158-164.
  4. Human centered design processes for interactive systems. International Organization for Standardization (1990) ISO 13407.
  5. Vanderheiden, G.C., & Tobias, J. (2000). Universal design of consumer products: Current industry practice. Madison, WI: Trace Research and Development Center. Retrieved on 1/13/05 from
  6. White, G.W., Suchowierska, M.A., & Campbell, M. Developing and systematically implementing participatory action research. Arch of Phys Med Rehabil, 85:2, April 2004.


R. L. Grubbs
Georgia Tech’s Center for Assistive Technology & Environmental Access (CATEA)
490 Tenth Street
Atlanta, GA 30318