The ICT Lounge
 
Section 8.1:
What is Systems Analysis and Design?
 
In this section you will be introduced to systems analysis and design.

We will look at:
  • The purpose of systems analysis and design
  • A breakdown of the six stages of systems analysis
    and design

Key Concepts of this section:
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Understand the purpose of systems analysis and design.
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Be able to name the six stages of systems analysis and design.

Introduction to systems analysis and design
Key Words:
Analysis, Design, Systems Analysis and Design Stages

What is the purpose of systems analysis and design?
Examples:
Paper-based systems are not very efficient and by analysing them we can identify improvements which can be developed into a computer-based system.
 
Computer-based systems are much more efficient.
 
Systems analysis and design can help eliminate faults and errors within the completed system.
System plans (designs) provide a blueprint for
system developers to follow.
 
Documentation (like user manuals) help people
to use the new system properly.
 
Completed system is tested and evaluated to see how well it is working.
 
NOTE:
Any problems found during testing and evaluation would be corrected and then re-tested.
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This is the process of looking at an existing system and then designing a new system that can carry out the same tasks better (e.g. a payroll system or billing system).

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If a system is developed without proper planning or design, serious faults and defects are usually found in the system later on when it has been built.

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Any faults discovered once the system has been built are very expensive and time-consuming to correct.

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By carrying out proper planning (systems analysis and design) before starting to build the system, these potential faults are minimised.

What is the 'Systems Analysis' part?
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This is where the existing system is looked at (analysed) in detail and improvements are suggested.

Existing systems that need to be improved are usually one of the following:
1.
A paper-based system with no current use of computers at all
2.
Computer-based system that is no longer good enough to handle the task.

What is the 'Design' part?
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This is where detailed plans are created for the proposed new system.

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The plans are carefully produced to make sure that the proposed system will carry out it's intended purpose. They also help to minimise faults and errors.

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These plans are like 'blueprints' for the system developers to follow.

A plan for a payroll system showing all the different parts of the system and how
they will communicate:

What are the six stages of systems analysis and design?
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The six stages (abbreviated to ADDIDE) are completed in the following order:

Analysis
Look at the existing system and find improvements

Design
Plan the proposed new system

Development and Testing
Create the new system and test it

Implementation
Place the new system into the company

Documentation
Create user-guides for every day users and those who will develop it further

Evaluation
Decide how well the new system is working
 

THESE STAGES WILL BE DISCUSSED IN MORE DETAIL
OVER THE NEXT FEW PAGES