Information Technology - The Design Phase: factors to be considered when
designing the output requirements
The Design Phase: factors to be considered when designing the output
In the Design Phase it is usual practice for programmers to begin by
identifying the output requirements of the proposed system.
There are a number of output devices that can be incorporated into any
Consider why the manner in which output is to be created and/or
displayed is actually of great significance to the design of a computer
If output is primarily screen based then the dimensions of the output
screens is a determining factor and must be considered when designing
If the system is to collect pictures that are displayed over the web,
then the file size will not have to be as large as those that will be
In a top down approach to system design, the programmer will start by
identifying the output that the system will need to produce. There are a
number of possible output formats that must be considered, including such
items as: printer, screen, plotter, audio, email, links to web pages,
automated fax facilities and computer output microfilm. There are many more
possible output devices that could be incorporated into any system - it
will depend on the technology that is available to the developers.
There are sound reasons for starting the system development with the
design of the output. The system will be implemented to help improve
efficiencies or to solve a problem. In order to do this, the first step
will be to determine what can be done to help the situation. Once this has
been done, a clear picture of what has to be produced can be identified.
This will shape the output requirements of the system. While the output may
seem to be the last part of the system that should be developed, it should
not be. In order to make the system a success it must be able to produce
the outcomes that can solve the problem, therefore the output required
needs to be identified early in the process.
Once the output has been identified, it will place constraints on the
system. These constraints will include requirements of data to be collected
to produce the output, and to the limitations imposed by the technologies
used to create the output. While it may sound minor, the manner in which
output is to be created and/or displayed is actually of great significance
to the design of a computer system. This is because it can quickly change
the nature of the resources that are required by the system to produce the
output. For example, if the system is to collect pictures that are
displayed over the web, then the file size will not have to be as large as
those that will be printed.
Some of the major constraints on output include:
Printers - the print quality, e.g. Laser/inkjet/colour, and the nature of
the information to be produced. For example, if a receipt is to be printed
and needs to be made in duplicate, then an impact printer will need to be
used or the item printed twice.
Screen - If the output is primarily to be screen based, then the screen
will impose a number of limitations on the output. The output will need to
be designed to fit into the screen size. If the screen is monochrome, then
colour cannot be used, etc.
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