1. Systems and Software
Development
1.1 The Systems Life Cycle
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1.1.1 The Basic Cycle
The basic cycle
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Why a cycle?
• All information systems need to change and
evolve because of:
‣ expansion of a business or one of its
operations,
‣ development of new business activities,
‣ the economic situation,
‣ technological advances, etc.
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Why a cycle?
• Changes nearly always involve greater use of
computer systems which are used over long
periods of time.
• Software in these systems requires
occasional improvement.
• After the original design and implementation,
further analysis, redesign and restructuring
are required to accommodate changing
needs.
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Why a cycle?
• This will continue through many cycles of
analysis, design, implementation and use.
• The whole project will cycle (possibly over a
period of years), each phase provides
information for the next.
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Why computerise?
• If there is a larger amount of data that
requires repetitive processing.
• If there is a need for better access to up-todate information.
• If clerical costs could be reduced.
• If there are indirect benefits to customer
service or cash flow.
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