User-Centered Design of Information Technology - Fundamentals and Assessment Tools for Occupational Ergonomics - page 146

Along with the requirements document, which explicitly lays out the system specifications, the models
and representations of the work system are used to guide the potential design alternatives. For example,
personas, story boards, use cases, and decision action diagrams could be used to help envision the order

and organization in which the system provides content or functionality in order to support the natural
workflow of the end-user. However, this process requires a clear and accurate interpretation of the data
and creative ingenuity to meet all of the functional and nonfunctional requirements, while working
within the constraints of the organization or environment. In fact, the boundaries and limitations
created by constraints on the system help design by reducing the number of possible design alternatives
(e.g., if the system needs to be implemented in Java TM ). If a design solution meets all of these require-
ments and can be elegant and appealing to users, then designers have truly earned their keep.
As mentioned previously, the transition from requirements to tangible design is somewhat nebulous.
Design solutions arise from the requirements in many ways, but progress and mature through iterative
development. Designers and their teams should accept a process of iterative prototyping, developing first
a low-fidelity mockup, and iteratively integrating feedback from evaluations of the prototype into
redesigns incrementally until a final working simulation is produced. Ideally, the design process
should gradually iterate on several prototypes, although this may necessarily be realistically feasible or
affordable given the constraints and resources associated with the project. At the minimum, however,
the process should incorporate at least one low-cost low- fidelity prototype in the design of a final
operational system. In fact, the value of design information garnered from the testing and evaluation
of low-fidelity, low-cost prototypes lies in the considerable positive influence of this collected insight
on the ultimate production of usable, useful, attractive final designs (Hall, 2001).

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7.3.2.6.3 Design Production: Prototyping
In his summary of UCD methods and techniques, Maguire (2001) provides a comprehensive review of
nine methods, which facilitate the design production step of UCD. Figure 7.4 illustrates different
methods for prototyping according to the number of design alternatives typically generated juxtaposed
with the level of fidelity the prototypes exude. The level of fidelity integrated into a design option is
directly proportional to the number of prototypes typically generated with such techniques and
related to the cost and time involved in the prototype building. Additionally, any prototype developed
should be done so with the foresight of realistic evaluations that the design and development team

FIGURE 7.4 Classification of commonly used prototyping methods.