The document outlines the key stages in the systems life cycle including analysis, design, development, testing and implementation, evaluation and maintenance, and documentation. Analysis involves feasibility studies, data collection, and requirements specification. Design includes output, input, and process design as well as hardware and software selection. Development is when programming and data structures are created. Testing and implementation involves testing modules and the whole system, then implementing using various strategies. Evaluation assesses the system and maintenance includes perfective, corrective and adaptive changes. Documentation covers technical details for specialists and user guides.

1. Unit 4: Systems Life Cycle
9713 AS Applied ICT
19713 AS Applied ICT - Unit 4

2. Analysis
• Feasibility Study
• Data Collection
• Requirements Specification
9713 AS Applied ICT - Unit 4 2

3. Feasibility Study
• Is the project ‘doable’?
• Does the technology exist?
• Do we really need it?
• Cost vs. Benefit
9713 AS Applied ICT - Unit 4 3

4. Data Collection
• Document Collection
• Questionnaires
• Interviews
• Observation (inc. Hawthorne effect)
When data is collected:
• Produce Data Flow Diagrams, System
Flowcharts
9713 AS Applied ICT - Unit 4 4

5. Requirements Specification
• Identifying the user and information
requirements by collating the interview
transcripts, questionnaires and documents
• Requirements Specification serves as a specific
contract between the user and the system
analyst
9713 AS Applied ICT - Unit 4 5

6. Design
• Output design
• Input design
• Process design
• Validation routines design
• Identifying suitable hardware and software
• Choose: Off-the-shelf or bespoke software
9713 AS Applied ICT - Unit 4 6

7. Design contd.
• Output: The content and presentation of reports,
layouts and screen displays depend on the
requirements of the users
• Input: Data collection forms and screen layouts
depend on the user requirements as well as output
required from system and file structures
• Process: Data/file structures and programming
depend on the types of processing, and input and
output structures

8. Development
• Creating data structures and program
modules (actual ‘programming’)
• Testing strategies

9. Testing and Implementation
Testing
• Testing each module with
1. Normal
2. Live
3. Abnormal
4. Extreme
data
• Testing whole system, stating expected vs.
actual outcome

10. Testing and Implementation
Implementation
1. Direct Changeover (‘Big Bang’)
2. Parallel Running
3. Phased Implementation
4. Pilot Running

11. Evaluation and Maintenance
Evaluation: Evaluating a new system in
terms of the efficiency, ease of use and
appropriateness of the solution by:
•Using test results
•Obtaining feedback from the user
Discovered limitations are used to make
improvements

12. Evaluation and Maintenance
Maintenance:
• Perfective
• Corrective
• Adaptive

13. Documentation
• Technical documentation
• User documentation

14. Technical documentation
For specialists, system administrators
• Systems documentation: Results of systems
analysis, what is expected of the system, test
plan and test data
• Program documentation: Description of the
software, purpose of the software, input data
formats, output, flowcharts, program listing

15. User documentation
For end users of system
• A guide to simple elements of use of the
software and hardware that make up the
system
• Troubleshooting