System Analysis, Design and Project Management
Domain 8 - System analysis, design and project management
Tests requirements gathering, process modelling, design tools and scheduling.
Core rules
- Feasibility: technical, economic, legal, operational and schedule.
- Waterfall is sequential and document-heavy; agile is iterative with frequent feedback.
- DFD shows processes, data stores, external entities and data flows; levelled DFDs must balance.
- UML use case shows actors and goals; class diagram shows classes and relationships.
- Project scheduling: Gantt shows timing; network diagram/CPM shows dependencies; critical path = longest duration with zero float.
Worked example
Tasks: A=3 days (no dependency), B=4 days after A, C=2 days after A, D=5 days after B and C. Paths: A–B–D = 3+4+5 = 12 days; A–C–D = 3+2+5 = 10 days. Critical path is A–B–D, so minimum project duration is 12 days. B has zero float on the critical path; C has 2 days float because it can finish 2 days later without delaying D. Reasoning: D waits for both B and C, so the longer incoming path controls.
Traps
Do not confuse Gantt bars with dependency logic. Requirements state what; design states how. In DFDs, do not show control flows or timing. Critical path is longest, not shortest. A use case is not a sequence diagram.