PMI-SP common mistakes
PMI-SP · Understand the traps and how to avoid them.
Jumping straight to a scheduling technique (Monte Carlo simulation, resource leveling, critical chain) because it sounds most rigorous, without first answering the strategy-level question of which scheduling method and tool the project requires.
Candidates equate 'advanced' with 'correct' and skim the question stem, which usually specifies project size, contractual constraints, or an existing organizational scheduling tool that rules out the sophisticated option.
What to do instead
Before evaluating options, force yourself to state in one sentence what the question is asking you to select: method, tool, or model detail. Schedule strategy is decided in the order scheduling method, then scheduling tool, then schedule model detail, so eliminate any option that skips a step in that chain.
Treating imposed dates, contractual milestones, and mandated calendars as negotiable planning variables and building a schedule that ignores them, then selecting answers that 'improve' the schedule by moving them.
Real-world experience teaches that dates are negotiable; the exam treats contractual and imposed dates as fixed constraints that must be absorbed by the plan, so experience-based answers look reasonable but are wrong.
What to do instead
Scan the stem for words like contractual, mandated, regulatory, or client-imposed and lock those as non-negotiable. Build the logic around them and look for answers that acknowledge the constraint, escalate it, or absorb it through float or contingency rather than answers that move the date.
Mixing up resource leveling and resource smoothing, choosing leveling when the question says the finish date must not slip, or choosing smoothing when the question demands a hard limit on a resource.
Both terms sound like 'fixing resources' and are often memorized as a pair of definitions without the distinguishing consequence: leveling may change the critical path and extend the duration; smoothing works only within existing float and preserves the duration.
What to do instead
Anchor each term to one phrase you can recall under pressure: leveling equals date may change; smoothing equals date must not change. Then eliminate any option whose consequence contradicts the constraint stated in the stem.
Computing float and logic dates incorrectly by treating free float and total float as interchangeable, ignoring lag and lead signs on finish-to-start versus start-to-start relationships, or forgetting that activity calendars, not just the project calendar, drive dates.
Candidates memorize ES, EF, LS, LF formulas but rehearse them on clean, lag-free networks; exam items deliberately add lags, multiple calendars, and non-standard relationships, so the mechanics break down.
What to do instead
Practice on networks that contain mixed relationship types, positive and negative lag, and at least one activity on a different calendar. Before computing, write down the relationship type, lag value, and calendar for each link so the arithmetic has a defined basis.
Declaring the project on schedule because the schedule performance index is at or near 1.0, even though the stem shows the critical path running behind and near-critical paths consuming float.
Earned value indices aggregate across all work and dilute the effect of one late critical-path activity; candidates reach for the familiar formula instead of reading the network logic in the question.
What to do instead
On any schedule-status question, check the critical path first and the earned value indices second. If the stem gives float consumption or path-level data, that data outranks an aggregate index, and the correct answer will usually be a corrective action on the specific path.
Choosing fast tracking when the affected activities have mandatory dependencies or high rework risk, or choosing crashing when the stem states cost is capped or resources are unavailable, instead of matching the compression technique to the stated constraint.
Both techniques shorten duration, so candidates pick whichever they have used in practice rather than testing each technique against the constraint the stem explicitly supplies.
What to do instead
Build a two-column check before selecting: what does fast tracking require (discretionary dependencies, tolerance for rework), and what does crashing require (extra cost, available resources). Eliminate the technique whose requirements the stem blocks.
Updating schedule baseline dates directly to reflect actual performance or an approved acceleration, and reporting against the revised baseline, without routing the change through integrated change control first.
Schedule software makes baseline changes a single click, so practitioners habitually rebaseline; the exam separates performance measurement baseline changes from ordinary status updates.
What to do instead
Classify the change out loud: if it alters scope, dates, or the approved schedule baseline, it needs a change request and approval before the baseline is touched. Only working-schedule updates and forecast dates can be adjusted without that step; reserve rebaselining for approved, formally documented changes.
Treating schedule closeout as simply producing a final status report and skipping the archival of the schedule model, the schedule lessons learned, and the update to organizational process assets.
Closeout is under-represented in day-to-day practice, so candidates pick the reporting-flavored answer because it feels like the visible end of a project.
What to do instead
Memorize closeout as a set of outputs, not a report: archived schedule model and baselines, final schedule performance information, lessons learned captured for future estimates and duration databases, and updates to organizational process assets. Eliminate monitoring-and-controlling activities such as variance analysis or forecast updates from closeout questions.
Confusing administrative closure outputs with contract closure outputs, or selecting a monitoring activity (performance review, variance analysis) when the stem is describing the end of a phase or project.
Both closures involve documentation and sign-off, and candidates blur the two because they are usually taught in the same chapter without a clean contrast.
What to do instead
Use the boundary test: does the stem mention a seller, procurement, or contract terms, or does it mention the project or phase records and lessons learned? Contract closure answers reference contract terms and formal acceptance of deliverables; administrative closure answers reference project records, final reports, and process asset updates.
Sending the full, unedited schedule model output to every stakeholder, or skipping the notification step and letting stakeholders discover date changes when the next report arrives.
Candidates focus on the technical accuracy of the data and treat communication as a passive byproduct, forgetting that the communication management plan defines audience, format, frequency, and method for schedule information.
What to do instead
Before selecting, identify the audience and what the communication management plan prescribes for them; a schedule report for executives is a tailored summary, not raw CPM data. On any question involving a date change, expect the correct answer to communicate to affected stakeholders before or as the change is implemented, not after.
Answering from personal experience with a particular scheduling tool or delivery approach rather than from the standard framework, and picking the answer that describes what your organization would do instead of the answer that matches the standard process order.
Experienced candidates are penalized by their own habits; the exam rewards the standard process sequence, and locally common shortcuts look like defensible options.
What to do instead
For each question, ask which standard process step the stem is located in, then choose the action that belongs to that step. If an option describes a shortcut you have personally taken, treat it as suspect and re-derive the answer from the process flow rather than from memory of practice.