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. |
|
|
# |
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).
|
# |
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.
|
# |
Any faults discovered once the system has been built are very expensive and time-consuming to correct.
|
# |
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? |
# |
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? |
#
|
This is where detailed plans are created for the proposed new system.
|
# |
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.
|
# |
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? |
# |
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
|
| |
