Scope, Schedule, and Cost Planning
What this domain tests
Scope, schedule, and cost planning: requirements, WBS, baselines, dependency logic, critical path, estimating, and budget reserves.
Core rules
- Scope baseline = scope statement + WBS + WBS dictionary. The WBS is deliverable-oriented; work packages are estimable and assignable.
- Schedule baseline comes from network logic: dependencies, leads/lags, durations, and resources. The critical path is the longest path through the network and has the least total float, usually zero.
- Total float = late start - early start (or late finish - early finish). Float is not extra time to waste; it shows scheduling flexibility.
- Cost baseline excludes management reserve; contingency reserve covers identified risks and is in the baseline. Management reserve covers unknown-unknowns and needs approval.
- Estimates range from rough order of magnitude to definitive. Analogous estimating is fast but less accurate; bottom-up is slower but more accurate.
Worked example
A small network: A=3 days; B=2 days after A; C=4 days after A; D=2 days after B and C. Paths: A-B-D = 7 days; A-C-D = 9 days. Critical path is A-C-D, duration 9. B has total float = 9 - 7 = 2 days. If B slips one day, the project finish does not move; if C slips one day, finish moves one day. Reasoning: compare path lengths, then protect the longest path.
Traps
- Calling the shortest path critical; critical means longest and least float.
- Adding contingency to every estimate without a risk basis.
- Confusing management reserve with contingency reserve.
- Using the WBS as an org chart or task list instead of deliverables.