Guidelines on design for dynamic and diverse use situations
As opposed to tailored products, industrially manufactured products are used by different user, for different purposes in different contexts of use. I call this dynamic and diverse use situations (DDUS). Dynamic use situations refer to the change of situations in time for one product, for example, one day you might use your bike to cycle to university to be in time for a lecture, while the next day you might use it to transport your groceries from the supermarket to your home. Diverse use situations refer to the change of situations in time and space for different versions of the same product. For example, someone else might possess the same type of bike, but only uses it for recreational purposes, for example cycling with friends. Design for DDUS is difficult because it is hard to predict the variety of use situations a product will encounter, it is hard to anticipate what kind of issues will occur when the designed product will interact with these situations and it is hard to deal with conflicting requirements from the different use situations in one design. Design for DDUS is not new in the sense that it recognizes the difficulties of dealing with different users in different contexts, because this issue is mentioned in many sources. However, those sources give little guidance on how to deal with this problem in design. Therefore I developed a set of guidelines to support designers in dealing with DDUS in the design process.
As mentioned in the introduction, the ISO-definition of usability is: “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.” (ISO, 1998: p.2) This definition suggests that usability can only be defined for a specified use situation: a specified user, goal and context. However, in practice products are used by varying users, for different goals in varying contexts of use. I define this issue as ‘design for dynamic and diverse use situations’ (DDUS). Designing for DDUS is difficult because it is hard to predict which situations a product will encounter, and consequently what this means for usability. Although this issue is acknowledged in the design research field, little guidance can be found on how to deal with it in design.
The goal of this study was firstly to gain insights in how designers currently deal with design for dynamic use situations. Secondly, guidelines were developed to support designers in tackling this design problem.
Method and results
How designers currently deal with dynamic use situations was studied by means of a retrospective case study of three design projects at Oce, Philips and Indes (Van der Bijl-Brouwer and van der Voort, 2009). This study concluded that there are different types of solutions to accommodate products to DDUS. These solutions revealed no particular problems for designers. The analysis of the design processes, however, did lead to a point of departure for development of a support tool. Although all participating product developers were aware of the dynamics and diversity of use situations, their knowledge of users, contexts and goals often remained implicit and was mostly not shared. As a consequence, evaluations of solutions sometimes tended to have an opportunistic character and did not reflect the use situations at which the product was aimed.
A support tool was developed which consists of a set of guidelines aimed at generating and applying an evolving explicit frame of reference of product use which can be used to set up use evaluations, to share knowledge on product use in a design team and to inspire solution generation. Furthermore the Envisioning Use workshop technique was developed, which is aimed at sharing knowledge about usability and use situations and building a first frame of reference of product use.
The guidelines for design for dynamic and diverse use situations form a practical support in dealing with different users and contexts of use in the design process. They are not intended as a replacement for an existing design process, but are represented in such a way that they can be accommodated to the current way of working. The guidelines are unique in the sense that they can lead to an approach which makes dynamic and diverse situations explicit in the design process and thereby makes it possible to take them into account.
Since the success of the guidelines can only be validated in a complete design process, it was chosen to validate the guidelines in two student projects, because this process can easily be observed and it does not require any financial risks from companies. The design projects were based on real cases, in order to be representative for a realistic design situation. The first project was executed with Bongo innovations BV, a producer of carrier bikes. The guidelines were adjusted based on the results of this project. The second validation took place with Philips Consumer lifestyle and concerned the redesign of the Philips Airfryer.
Valorisation (booklet) and benefits
The guidelines are presented in a concise workbook and the Envisioning Use workshop is presented in a manual booklet. The guidelines can support companies in inspiring designers and usability engineers to accommodate their design and evaluation process to the dynamic and diverse aspects of use situations. The booklet with guidelines can be found on the Results page.