6.2 Systems Development Life Cycle
It is a another name given for systems development process. The following diagram
illustrate the system development life cycle and its main phases.
6.2.1 Traditional System Development Life Cycle
Some times, information learned in a particular phase requires cycling back to previous
phase.
6.2.2. Prototyping
Prototyping takes an iterative approach during the systems development
life cycle.
The following activities take place during each iteration of the life cycle.
- Requirements are identified and analyzed
- Alternative Solutions are identified and analyzed
- New solutions are designed
- Portion of the system is also implemented
- Users are encouraged to use the prototype and provide feed back
At the beginning either you develop an initial model of a major subsystem or scale down
version of the entire system.
Eg. Prototype develop to show the screen images of the entire system. Initial processing
activities will be simulated. You will refine it gradually to build the actual system.
Visual Basic is considered as a good language for prototyping.
Initial preliminary model will be polished to form the next generation prototype. This process
continues until the final system is developed.
6.2.3. Rapid Application Development (RAD)
Tools, techniques methodologies are used in this popular approach to speed up the
development. It uses structured prototyping.
RAD is the merger of various structured techniques with prototyping techniques and Joint
Application Development (JAD) techniques to accelerate systems development.
Joint Application Development emphasize participative development among
users, and others involved with the system.
RAD is considered as most suitable for Decision Support Systems and Management
Information systems.
Other approaches to rapid development such as Agile Development or Extreme
programming (XP), allow system modifications while they are been developed.
6.2.4. End-User Systems Development
The term end-user systems development describes any systems development project in
which the primary effort is undertaken by a combination of business managers and users.
The flexibility of many packaged software programs available in the market has also
enabled non IS employees to develop solutions to meet their requirements. Employees who
develop their own systems believe that by bypassing formal requests to the IS department
stating the required needs and resources, they are able to develop systems more quickly.
Furthermore, they believe they have a clear idea as to what is required and therefore able to
develop systems that match their requirements.
End-user development projects can vary from the size. Some may be very minor projects
such as the development of an additional report. There can also be projects with significant
organizational value such as development of a system to monitor on-line customer contacts.
Two disadvantages of end-user development are lack of training to effectively develop and
test a system and poor documentation. Lack of documentation can lead to errors when
these systems are updated.
However, due to the importance of some of the end-user developments many IS
organizations help end-user development by providing them with necessary resources.
6.2.5 Outsourcing Systems for System Development
The term outsourcing means the practice of turning over part or all of an organisations IS
functions to external service providers for a fee. Organisations can outsource its software
development rather than developing it internally. There are advantages as well as
disadvantages of outsourcing. However, many organisations consider it as a cost effective
approach.
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