begin the analysis. list of objectivescriteria ... analyse

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THE SYSTEMS LIFE CYCLE
5 POINT PLAN
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Identify/Investigate problem
1. How does the current system operate
2. What does the current system not do
3. What should the new system be able to do
4. What are some alternative solutions
5. A recommended course of action
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If the Identification recommends that the project
can go ahead

• Make out a list of Objectives/Criteria
• Begin the Analysis

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List of Objectives/Criteria
These should be kept simple and should be
referred to throughout the coursework to ensure
you are achieving what you set out to do eg.

• The output must be easy to read and understand
• Test the solution using suitable test data
• Produce a template that can be re used

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Analyse The Problem
Examine what problems exist within the current
system by asking questions
What is being done now ?
Why is it being done ?
Who is doing it ?
How is it being done ?
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Analyse The Problem
Fact-finding methods used to gather information
Questionnaires
Interviews
Observation
Examining Docs
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The investigation is used to produce a detailed
description of the current system including the
use of Data Flow Diagrams and Systems
Flowcharts See page 216 to 219 of text
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Design A Solution
Identify the alternative possible solutions
What hardware does the solution require ?
What benefits does this new solution offer ?
What are the drawbacks of this solution ?
How long will development take ?
How much will this solution cost ?
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Design A Solution
Having identified the best solution produce a
detailed design specification
Input
Back up procedures
Output
Security Procedures
Data Storage
Test Plan
User Interface
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Implement A solution
Set up the system so that it matches the design
specification
Create data files
Set up the user interface
Set up validation checks
Set up system security
Enter enough data to test the system
Create input/output screens
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Implement A solution
When testing the system use the plan prepared
during the design stage
Normal data - expected during day to day use
Extreme data - data that lies at the boundaries
of acceptable input
Erroneous data - data that lies outwith the
boundaries
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Implement A solution
It is now possible to install the new system
Direct Implementation - Instantaneous change
from old to new system. Quick but very disruptive
if errors found
Parallel Implementation - Run both systems
simultaneously over a period. Longer to operate.
No disruption from errors
Phased Implementation - Introduce the new system
in smaller parts
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Implement A solution
Finally, documentation must be produced for the
system
Technical Documentation
User Documentation
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Implement A solution
Technical Documentation
System Design Specification
Description of the system
Flowcharts
Screen Layouts and UI Designs
The Test Plan
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Implement A solution
User Documentation
Additional Support Help Lines
Minimum System requirements
Loading Instructions
Meaning of Error Messages
Operating instructions
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Maintenance

• Some time after installation, a new system may
  need to be changed
• to satisfy the needs of the user
• to correct problems
• to improve the system

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Evaluation
The solution to each problem must be evaluated to
check its success
Is the PROBLEM solved ?
Have the Objectives/criteria been met ?
Did the test data work ?
How can the system be improved ?
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Chapter 10 pgs 215 - 244 gives a detailed
breakdown of the requirements to be met for your
coursework projects