Which activity controls the finish date?
The project has nine working days until its promised handover. A sponsor offers help, but wants to know where it will matter.
The question
Alder Works and all estimates are fictional. Day 0 is the start. Tasks start immediately when predecessors finish. Durations are whole working days; no holidays, resource conflicts or hidden lags apply except those stated.
| Duration (days) | Must follow | |
|---|---|---|
| A: Environment setup | 2 | Start |
| B: Configure workflow | 5 | A |
| C: Train local leads | 3 | A |
| D: Acceptance test | 2 | B and C |
B and C can run in parallel after A. D starts only when both finish.
The sponsor must approve extra spend. The handover target is the end of day 9.
“Choose your next action and explain the evidence behind it.”
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A strong answer, step by step
Open each step in turn. This is one strong answer, not the only one.
Step 1: What is the baseline finish?
What would you do here? Open the move you’d make.
Trace both dependency paths
The strong move. The longest dependency path controls this finish date.
Add all four durations and promise day 12.
Tempting, but it misses something. B and C can run in parallel.
See how a strong candidate says it
“A–B–D takes 2 + 5 + 2 = 9 days. A–C–D takes 7, so training has 2 days of float.”
Why it works: The longest dependency path controls this finish date.
Step 2: Where should help go?
What would you do here? Open the move you’d make.
Check the controlling path
The strong move. Finishing C earlier cannot shorten a path already two days shorter.
Buy faster training because it is easy to arrange.
Tempting, but it misses something. That does not shorten the controlling path.
See how a strong candidate says it
“Check the availability and estimates on A–B–D before accelerating training.”
Why it works: Finishing C earlier cannot shorten a path already two days shorter.
Step 3: What is the revised date?
The configuration owner confirms that an external review adds 2 working days to B. B now takes 7 days. All other durations and dependencies stay unchanged.
What would you do here? Open the move you’d make.
Revise the finish date
The strong move. The confirmed estimate changes the controlling path.
Keep day 9 because training still has spare time.
Tempting, but it misses something. Spare time on C cannot replace work on B.
See how a strong candidate says it
“Configuration now takes 7 days. The finish is day 11, two days late.”
Why it works: The confirmed estimate changes the controlling path.
Step 4: What recovery is worth approving?
A qualified specialist can remove the 2-day delay from B for $800 per day. The configuration owner confirms that scope and acceptance testing remain intact. The specialist is available only if the sponsor approves today.
What would you do here? Open the move you’d make.
Seek recovery approval
The strong move. This option removes the delay on the controlling path; the sponsor still owns the spend.
Approve the spend yourself and remove acceptance testing to gain time.
Tempting, but it misses something. The PM lacks spend approval, and the acceptance check remains required.
See how a strong candidate says it
“Seek approval for the specialist: 2 × $800 = $1,600 restores B to 5 days and the finish to day 9.”
Why it works: This option removes the delay on the controlling path; the sponsor still owns the spend.
The answer, in short
- Decision
- Ask for the $1,600 recovery approval with day 11 as the unrecovered forecast.
- Because
- The funded option removes two days from the controlling activity.
- What would change it
- A changed estimate, specialist availability or sponsor refusal.
Common traps
- Float on one path is not spare capacity on another.
- A recovery plan is not approved merely because it is feasible.
Check your answer
- I traced both paths.
- I identified the controlling activity.
- I revised the finish date.
- I kept the sponsor’s approval explicit.
Last reviewed Nov 10, 2026