A user of the program only interacts with a program through
the user interface so it makes sense to spend a significant amount of time
during requirements to ensure that the user interface makes sense, that all
functionality is included, and that the most commonly used functionality is
easily accessible. The easiest way of doing this is using a screen prototype.
There are a variety of methods of making screen prototypes
which range from simply drawing the interface with a pen and paper to building
“working” prototypes in a higher level language like Visual Basic which allows
rapid screen design. However, each of these extremes has serious drawbacks. A
pen and paper prototype does not allow users to interact with the prototype and
it is more difficult to change. A “working” prototype done in a programming
language like Visual Basic can lead the client to believe that the program is
nearly complete and that development should not take very long or it can lead
the client to believe that changes to the prototype will be costly, making them
reluctant to make necessary suggestions to improve the program.
Between these two extremes lies screen design applications
which allow you to draw the screens and model interactions between screens.
High quality prototyping tools allow you to enter sample data and allow users
to move between screens by pressing buttons so they can easily understand the
interface and its functionality. Most prototyping tools produce the final
output in an HTML format so they can be easily shared even if a client is not
in the same office where requirements are being developed.
When looking for a prototyping tool, make sure to select a
tool which is easy enough to use that you can easily prototype screens while
your customer is in the room. This will allow you to brainstorm and make
changes to the screens without delays. A prototyping tool should already have
common controls already defined to maintain design standards and improve the
appearance of your screens. Being able to enter sample data in each screen can
allow the customer to pinpoint areas that may be incorrect.