The software development
process is almost invariably guided by
some systematic software development method (SDM).
Referred to by a number of terms, including process
models, development guidelines, and
systems development life cycle models (SDLC), software
development methods nevertheless generally include
the same development phases:
The existing system is evaluated and its
deficiencies identified, usually through interviewing system users and support personnel.
The new system requirements are defined. In
particular, the deficiencies in the existing
system must be addressed with specific proposals for
improvement.
The proposed system is designed. Plans are laid
out concerning the physical construction, hardware,
operating systems, programming, communications, and
security issues.
The new system is developed.
The new components and programs must
be obtained and installed.
Users of the system must be trained
in its use, and all aspects of performance
must be tested. If necessary, adjustments
must be made at this stage.
The system is put into use. This can be done in
various ways. The new system can phased in,according
to application or location, and the old system
gradually replaced. In some cases, it may be more
cost-effective to shut down the old system and
implement the new system all at once.
Once the new system is up and running for awhile,
it should be exhaustively evaluated. Maintenance must
be kept up rigorously at all times. Users of the
system should be kept up- to-date concerning the latest
modifications and procedures.
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