CIE AS Level Applied ICT Unit 4 - Systems Life Cycle
- 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