September 7, 2026 · 8 min read
TL;DR: Options that crash or fast-track appear 26 times in this bank and are keyed 4 times. The four that work share one feature: the scenario has already established a schedule shortfall on the critical path, and the compression is authorized. The 22 failures compress the wrong thing, at the wrong time, or without permission.
Schedule compression is the most technically specific recovery tool the exam gives you, and that specificity is the trap. Candidates learn crashing and fast-tracking as the answer to "the project is late," which is roughly like learning that antibiotics are the answer to "the patient is unwell."
We counted every option in the 2,141 questions here that crashes, fast-tracks or compresses. Four are keyed. The pattern in the other 22 is unusually clean.
Three things, in order: is the problem actually schedule, is the target actually on the critical path, and are you actually allowed.
Consider a steel-mill upgrade. The structural steel erection finished on schedule, then a market shortage sends plate prices sharply higher. Current performance: CPI 1.01, SPI 0.76.
Work the numbers before you reach for a tool.
The keyed answer looks for opportunities to crash or fast-track the remaining work. The three distractors all chase the cost story the scenario dangles: renegotiate with suppliers, revise the cost estimates, report the cost deviation to stakeholders. The scenario spends two sentences on a price shock that the numbers say is irrelevant. That is the whole question.
Only discretionary ones, and the bank tests this directly.
One question puts a project three weeks behind with no budget to crash, and asks which dependencies to fast-track. The four options are industry-regulated, external, mandatory, and discretionary.
| Dependency type | What it is | Can you fast-track it? |
|---|---|---|
| Mandatory | Inherent in the nature of the work: concrete cures before load is applied | No. Not slow or expensive, impossible |
| External | Outside the project's control, such as a permit or a supplier | No. You do not own the sequence |
| Industry-regulated | Imposed by a standard or regulator | No. Compliance is not negotiable |
| Discretionary | Preferred logic the project chose, often team habit or best practice | Yes. The project imposed it, so the project can relax it |
Discretionary is keyed because it is the only sequence the project itself chose. Fast-tracking it trades a known rework risk for time, which is a trade the project is entitled to make. The other three are not slow to parallelise, they are not available to parallelise.
Common trap: reaching for compression before checking whether the delay touches the critical path at all. In one bank scenario a supplier warns that a fan drive may slip three weeks, and the keyed answer is to trace the installation through the critical path and its dependencies to establish whether three weeks moves the finish date at all. "Fast-track the project" and "press the supplier to expedite" are both distractors sitting beside it. Float is free; compression is not. This bank explains why each compression distractor loses instead of just marking it wrong, which is what turns four keyed cases into a rule you can apply to a question you have never seen.
Whenever it changes a committed date or spends money the plan did not allocate.
The bank has a customer request that would compress a project, and the keyed answer tells the customer how the request affects the project constraints and obtains the necessary approvals before crashing. Compression is not a private recovery lever. Crashing spends money, and fast-tracking accepts rework risk on the organization's behalf.
Compare that with the sick-leave scenario, where the only critical-path resource is out for two weeks with no replacement. Both "fast-track the project" and "crash the project" are offered. Both are distractors. The keyed answer notifies the stakeholders, because restructuring the plan and buying time with added risk or added cost is not the project manager's call to make before the people who agreed the date know it has moved.
There is one more counter-example worth keeping. When a project is behind schedule but running under budget, adding resources can be keyed rather than trapped. In one question, planned value is $840,000, earned value is $795,000 and actual cost is $755,000. Schedule variance is 795,000 minus 840,000, so negative $45,000, behind. Cost variance is 795,000 minus 755,000, so positive $40,000, under budget. The favourable cost variance is what makes buying back schedule legitimate: there is real money available for the trade. Compression is not banned. It is conditional, and the conditions are all in the numbers.
What is the difference between crashing and fast-tracking? Crashing adds resources to shorten duration and costs money. Fast-tracking runs sequential activities in parallel and costs rework risk instead. Both only shorten the project when applied to the critical path, and neither changes scope.
Which dependencies can be fast-tracked? Only discretionary ones. A bank question asks exactly this and keys discretionary dependencies, because they represent preferred logic the project chose and can therefore relax. Mandatory dependencies are inherent in the work, so parallelising them is not expensive, it is impossible.
When is crashing the wrong answer on the PMP exam? When the numbers show a cost problem rather than a schedule problem, when the compression has not been authorized, or when a cheaper diagnostic step has not been taken. Across this bank, compression options are keyed 4 times against 22 as distractors.
Do I need approval before crashing the schedule? If it changes a committed date or spends money outside the plan, yes. One bank question keys crashing only after the customer has been told how the request affects the constraints and the necessary approvals have been obtained.
PMP Practice's 2,141 questions are re-certified against PMBOK 8 and the July 2026 Exam Content Outline, with every wrong answer explained rather than just marked wrong, so a compression distractor tells you whether it failed on the diagnosis, the dependency, or the authorization. Start the free 20-question sample with no card and no signup.
Related: Critical Path Method (CPM) and Float and Overtime on the PMP Exam: The Answer the Bank Never Keys. The domain walkthrough is at /study/process.
What is the difference between crashing and fast-tracking?
Crashing adds resources to shorten duration and costs money. Fast-tracking runs sequential activities in parallel and costs rework risk instead. Both only shorten the project when applied to the critical path, and neither changes scope.
Which dependencies can be fast-tracked?
Only discretionary ones. A bank question asks exactly this and keys discretionary dependencies, because they represent preferred logic the project chose and can therefore relax. Mandatory dependencies are inherent in the work, so parallelising them is not expensive, it is impossible.
When is crashing the wrong answer on the PMP exam?
When the numbers show a cost problem rather than a schedule problem, when the compression has not been authorized, or when a cheaper diagnostic step has not been taken. Across this bank, compression options are keyed 4 times against 22 as distractors.
Do I need approval before crashing the schedule?
If it changes a committed date or spends money outside the plan, yes. One bank question keys crashing only after the customer has been told how the request affects the constraints and the necessary approvals have been obtained.