Rapid
Prototyping (software or hardware based)
Primary Reference Source
Isensee, S, & J Rudd (1966) The Art of Rapid Prototyping. International
Thomson Computer Press, London.
Summary Description
This method is concerned with developing different proposed concepts through
software or hardware prototypes, and evaluating them. In general the process
is termed ‘rapid’ prototyping. The development of a simulation or prototype
of the future system can be very helpful, allowing users to visualise the
system, and provide feedback on it. Thus it can be used to clarify user
requirements options.
Rapid prototyping is described as a computer-based method which aims
to reduce the iterative development cycle. Interactive prototypes are developed
which can be quickly replaced or changed in line with design feedback.
This feedback may be derived from colleagues or from the experiences of
users as they work with the prototype to accomplish set tasks.
Within software engineering circles the method is closely associated
with user interface management systems and various design support tools.
The latter tools offer the designer libraries of procedures and graphical
interface elements for defining the software’s logical structure and ‘look-and-feel’.
Here the title refers to an approach adopted by software developers in
which the prototypes exhibit a higher fidelity with the end product than
those created as part of other methods such as paper prototyping.
The method requires more sophisticated technical resources than is the
case with low-fidelity prototyping methods which rely on paper materials.
An additional cost of use is the level of human expertise required to master
the supporting development tools, along with the time necessary to implement
a software prototype. If user-based testing will be carried out with the
developing prototype, then resources for this activity will also be needed.
Benefits
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Permits the swift development of interactive software prototypes.
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Prototypes created by this method have a high fidelity with the final product.
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The prototypes created under this method support metric-based evaluations.
Limitations
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The method requires software development skills.
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Although rapid, the method is more time consuming than other approaches.
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The resources required are greater due to the need for software and hardware
rather than paper and pens.
Cost of use
Requires programming or model building skills to produce the prototypes.
A number of prototype iterations may be carried out or a parallel design
approach may be adopted. The process of obtaining user feedback will also
incur a certain amount of cost in terms of time and effort.
Suitability for requirements engineering in Telematics
Insofar as this is a generic approach which involves end users in the development
process, Rapid Prototyping is to be recommended. The necessary tools for
adopting this approach in a cost-effective way throughout the development
lifecycle may not be available for some application areas. See Isensee
& Rudd for more details about available tools.
Procedure
A general procedure for adopting the rapid prototyping method is outlined
below.
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Firstly, allow enough time to create the prototype. If the prototype is
to be evaluated with users then allow time to design relevant tasks, recruit
the users, evaluate the prototype and report the results.
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Assemble the necessary equipment, including the hardware and software tools
necessary to create the interactive prototype.
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Develop the prototype itself.
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Select appropriate users to test the prototype, trying to cover the range
of users within the target population. A facilitator will also be required
to instruct the users and run the evaluation.
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Prepare realistic tasks to occupy the users as they work with the prototype.
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Pilot the evaluation procedure and ensure the prototype can be used to
accomplish the tasks.
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Ensure recording facilities are available and functioning.
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Conduct each session. The facilitator instructs the user to work through
the allocated tasks, interacting with, and responding to, the system as
appropriate.
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If necessary additional information can be obtained by interviewing users
following their use of the prototype.
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Debrief and thank the user.
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Analyse the obtained information and then summarise the observations and
user evaluations. Determine the themes and severity of the problems identified.
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Summarise design implications and recommendations for improvements and
feed back to design team. Video recordings can support this.
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Where necessary refine the prototype and repeat the above process.