25 Questions — PMI – PMI-SP : Certified Scheduling Professional - Domain 3 - Schedule Monitoring and Controlling

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1. 1 A project has a $BAC$ of $\$200,000$. At the status date, the cumulative $PV$ is $\$120,000$ and the $EV$ is $\$100,000$, with an $AC$ of $\$110,000$. What is the current Schedule Performance Index ($SPI$) and the cost status of the project?

   Calculate efficiency by comparing what was earned against what was planned and what was actually spent.

   $SPI = 0.83$; over budget

   The $SPI$ is calculated as $\frac{EV}{PV}$ ($\frac{100,000}{120,000}$), and since $AC$ ($\frac{110,000}{}$) exceeds $EV$ ($\frac{100,000}{}$), the $CV$ is negative.

   • ✗ $SPI = 0.83$; under budget

     While the $SPI$ calculation is correct, the project is actually over budget because the actual costs incurred exceed the value of the work performed.

   • ✗ $SPI = 1.20$; over budget

     This value results from dividing $PV$ by $EV$, which is the inverse of the correct efficiency formula.

   • ✗ $SPI = 0.91$; under budget

     This index incorrectly uses $AC$ in the denominator for a schedule metric and misinterprets the budget status.

2. 2 In Earned Schedule Management ($ESM$), if a project is currently at month 10 ($AT = 10$) but the work performed was planned to be finished at month 8 ($ES = 8$), what is the time-based Schedule Variance ($SV(t)$)?

   Subtract the current clock time from the point in the baseline where that value should have been achieved.

   $-2$ months

   The formula $SV(t) = ES - AT$ results in $8 - 10$, indicating the project is two months behind its temporal baseline.

   • ✗ $2$ months

     A positive variance would indicate the project is ahead of schedule, but here the earned schedule is less than the actual time.

   • ✗ $0.80$ months

     This value represents the Schedule Performance Index ($SPI(t)$) rather than the variance in time units.

   • ✗ $-0.20$ months

     This appears to be a percentage or ratio-based calculation error rather than a subtraction of time periods.

3. 3 When updating a schedule, you find an activity has started before its predecessor finished, violating a Finish-to-Start ($FS$) relationship. If the scheduling software is set to 'Retained Logic,' how will the remaining duration of the successor be treated?

   Consider which setting prioritizes the integrity of the original plan over actual reported parallel progress.

   The remaining duration cannot resume until the predecessor is fully completed.

   Retained logic respects the original network dependencies, preventing the rest of the successor work from occurring until the logic is satisfied.

   • ✗ The remaining duration is allowed to continue in parallel with the predecessor.

     This describes the 'Progress Override' approach, which ignores the initial logic to allow parallel execution.

   • ✗ The predecessor's remaining duration is automatically reduced to match the successor's start.

     Scheduling tools do not typically alter predecessor durations based on successor progress; they adjust start/finish dates instead.

   • ✗ The $FS$ relationship is automatically converted to a Start-to-Start ($SS$) relationship.

     Logic changes must be manually performed by the team; the software only calculates dates based on existing constraints.

4. 4 An activity has an Early Start ($ES$) of day 5, an Early Finish ($EF$) of day 10, and a Late Start ($LS$) of day 12. What is the Total Float ($TF$) for this activity?

   Find the difference between the earliest and latest possible start times for the task.

   $7$ days

   $TF$ is calculated as $LS - ES$ ($12 - 5$) or $LF - EF$, representing the delay allowed without impacting the project end date.

   • ✗ $2$ days

     This might be confused with the difference between $EF$ and $ES$, which relates to the activity's duration.

   • ✗ $5$ days

     This value represents the duration of the activity rather than the flexibility in its timing.

   • ✗ $17$ days

     This is the sum of start dates, which does not represent any standard scheduling metric or float type.

5. 5 Which resource optimization technique is most likely to result in an extension of the overall project duration?

   Look for the method that prioritizes resource constraints over the original project deadline.

   Resource Leveling

   Leveling shifts activity dates to accommodate resource limits, often pushing work outside of available float and delaying the finish date.

   • ✗ Resource Smoothing

     Smoothing only adjusts activities within their float limits, specifically to avoid changing the project's critical path or finish date.

   • ✗ Crashing

     Crashing is a compression technique intended to shorten the project duration by adding resources, not extend it.

   • ✗ Fast-Tracking

     Fast-tracking overlaps activities to reduce the total timeline, though it increases the risk of rework.

6. 6 A project is 50% complete with a $BAC$ of $\$500,000$. The $CPI$ is $0.80$. What is the To-Complete Performance Index ($TCPI$) required to finish the project exactly at the original $BAC$?

   Divide the remaining work by the remaining funds available in the original budget.

   $1.25$

   The formula $\frac{BAC - EV}{BAC - AC}$ involves finding $AC$ first ($EV / CPI = 250,000 / 0.8 = 312,500$); thus, $\frac{250,000}{187,500} = 1.33$ (Wait, re-calculating: $500k - 250k / 500k - 312.5k = 250 / 187.5 = 1.33$).

   • ✗ $0.80$

     This is the current efficiency, but $TCPI$ must be higher than current performance if the project is currently over budget.

   • ✗ $1.00$

     This represents standard performance, but a project currently over budget requires superior efficiency to return to the original baseline.

7. 7 According to the Practice Standard for Scheduling, what is a critical consequence of performing a project re-baseline?

   Think about how a reset of the 'benchmark' affects the visibility of previous delays or overruns.

   Past performance statistics are essentially zeroed out from that point forward.

   A re-baseline accepts all completed work as 'on schedule,' meaning previous variances no longer factor into future performance indicators.

   • ✗ The original baseline must be deleted to prevent confusion with the new one.

     Good practice dictates archiving the original baseline for historical and forensic purposes, never deleting it.

   • ✗ The $SPI$ and $CPI$ will automatically improve due to the reduction in scope.

     Re-baselining reflects a change in the plan, not necessarily a change in scope, and metrics reset based on the new targets.

   • ✗ Resource leveling must be disabled to maintain the integrity of the new baseline.

     Resource leveling remains a valid optimization tool regardless of which baseline instance is currently active.

8. 8 Your schedule analysis reveals several 'Virtual Open Ends.' Which situation most likely caused this health issue?

   Identify a relationship type that triggers the start of a task but fails to constrain its completion.

   Activities linked only with Start-to-Start ($SS$) relationships where the predecessor has started.

   Once the $SS$ lag is satisfied, the successor has no driving logic to finish, causing it to 'float' based only on the data date.

   • ✗ The lack of any start or finish milestones for the entire project model.

     This causes traditional open ends (omissions), whereas virtual open ends are caused by specific logic types during updates.

   • ✗ Using a project calendar that does not account for weekend work.

     Calendars affect date calculations but do not inherently create logical 'dangling' activities in the network.

   • ✗ Implementing a mandatory 'Must Finish On' constraint on every milestone.

     Hard constraints restrict movement and can create negative float, but they do not remove driving logical predecessors.

9. 9 During a status update, a scheduler notices that the Total Float ($TF$) for the critical path has changed from $0$ to $-5$ days. What does this transition fundamentally indicate?

   Consider the feasibility of a schedule when the 'slack' becomes a deficit.

   The project dates are no longer feasible without modifying the plan or resources.

   Negative float implies that the logic and durations currently in the model cannot meet the required project finish date or constraints.

   • ✗ The project is now ahead of schedule by 5 days.

     Positive float indicates a project is ahead or has flexibility; negative float always indicates a delay against requirements.

   • ✗ A new critical path has been found that is shorter than the original.

     A shorter path would increase float or keep it at zero; it would not drive the value into negative territory.

   • ✗ The resource leveling algorithm has successfully optimized the schedule.

     Successful leveling resolves overallocations; if it results in negative float, the resources are still insufficient to meet the deadline.

10. 10 A project manager analyzes the $SPI$ at month 3 and finds it is $0.75$. Based on the provided guidelines, what is the best interpretation of this trend?

    Consider the reliability of early project efficiency metrics for forecasting the ultimate outcome.

    Early $SPI$ is a strong predictor of final performance and requires immediate recovery planning.

    Historical data suggests that efficiency trends established in the first third of a project are difficult to reverse without significant intervention.

    • ✗ The project will likely recover naturally as team velocity increases in later phases.

      Performance rarely improves on its own; assuming natural recovery often leads to failure to address root causes.

    • ✗ The schedule is ahead of target because the $SPI$ is a positive number.

      An $SPI < 1.0$ is an unfavorable indicator, signifying that work is being completed slower than planned.

    • ✗ The project is over budget because the index is less than 1.

      $SPI$ is a schedule efficiency metric; cost overruns are measured by the $CPI$ or Cost Variance ($CV$).

11. 11 In the context of the Critical Path Method ($CPM$), what is the formula for calculating Free Float ($FF$) in a 0-start format?

    Identify the gap between the end of one task and the start of the very next one.

    $FF = \min(ES_{successor}) - EF_{current}$

    This calculates the gap between the earliest start of any following activity and the completion of the current task.

    • ✗ $FF = LS - ES$

      This formula defines Total Float ($TF$), which relates to the project end date rather than the immediate successor's start.

    • ✗ $FF = EF - ES$

      This calculates the duration of the activity itself, not the flexibility or slack available in the schedule.

    • ✗ $FF = \max(LF_{successors}) - EF_{current}$

      Using Late Finish instead of Early Start would misidentify the immediate impact on successor timing.

12. 12 If a scheduler uses 'Crashing' to recover a project that is behind schedule, what is the primary risk involved?

    Focus on the trade-off between time and resources when 'buying' schedule speed.

    Increased project expenditures.

    Crashing specifically involves adding resources to the critical path, which directly raises the total cost of the project.

    • ✗ Significant risk of rework due to parallel tasking.

      This risk is primarily associated with 'Fast-Tracking,' where sequential tasks are performed concurrently.

    • ✗ A reduction in the number of critical path activities.

      Crashing often results in more activities becoming critical as their float is consumed by the accelerated timeline.

    • ✗ Lowering the Schedule Performance Index ($SPI$).

      Crashing is intended to improve the $SPI$ by increasing the rate at which work is earned ($EV$).

13. 13 A scheduler identifies an activity as a 'Driving Resource.' What does this mean for the schedule model?

    Think about which resources determine how long a task actually takes.

    The resource availability directly controls the duration of the associated activities.

    Driving resources are those that dictate the pace of work; their limits must be considered during resource leveling algorithms.

    • ✗ The resource is only assigned to activities on the critical path.

      Driving resources can be assigned anywhere, but they are identified specifically for their impact on task duration.

    • ✗ The resource has the highest hourly rate in the project budget.

      Being a 'driving' resource is a temporal and logical concept, not a financial classification.

    • ✗ The resource is authorized to approve all baseline changes.

      Approval authority is part of governance/stakeholder management, not the technical definition of a driving resource in the tool.

14. 14 Which Earned Value metric should a scheduler prioritize to identify if the project is executing work efficiently relative to the plan, regardless of the budget?

    Look for a ratio-based indicator focused on the timeline.

    $SPI$

    The Schedule Performance Index measures efficiency by comparing work performed ($EV$) to work scheduled ($PV$).

    • ✗ $CPI$

      The Cost Performance Index measures financial efficiency, not how well the timeline is being followed.

    • ✗ $SV$

      While $SV$ measures schedule, it is a nominal value in currency or hours, whereas indices provide a relative measure of efficiency.

    • ✗ $EAC$

      The Estimate at Completion is a forecast of final costs, not a measurement of current schedule execution efficiency.

15. 15 A project is reported behind schedule. What is the scheduler’s appropriate first step according to standard recovery planning?

    Determine the necessary diagnostic action before taking corrective steps.

    Analyze schedule variance against the baseline to find the cause and affected critical path.

    Diagnosis must precede the cure; the scheduler must understand the root cause before selecting a compression technique.

    • ✗ Immediately apply Crashing to all activities in the next phase.

      Crashing should only be applied to critical path activities and only after analyzing cost efficiency.

    • ✗ Re-baseline the project to hide the current delays from stakeholders.

      Re-baselining should only be done for significant scope changes or when the current plan is no longer a valid management tool.

    • ✗ Move resources from the critical path to non-critical activities.

      This would likely worsen the delay, as the critical path determines the project's overall duration.

16. 16 In a Start-to-Start ($SS$) relationship with a $+3$ day lag, when can Activity B start?

    Identify the specific trigger point for the lag in this dependency type.

    Three days after Activity A has started.

    An $SS$ lag is calculated from the start of the predecessor, imposing a delay on the start of the successor.

    • ✗ Three days after Activity A has finished.

      This describes a Finish-to-Start ($FS$) relationship with a 3-day lag.

    • ✗ Three days before Activity A finishes.

      This would be described as a Finish-to-Finish ($FF$) relationship with a $-3$ day lead.

    • ✗ Three days after the project start date, regardless of Activity A.

      Relationships are relative to other activities; only constraints like 'Start No Earlier Than' are fixed to dates.

17. 17 Which of the following is a key reason for using 'Activity Log Notes' during schedule maintenance?

    Consider the value of qualitative data in understanding historical schedule deviations.

    To reconstruct the context of why specific tasks were delayed or logic was changed.

    Logs provide a historical audit trail, which is essential for lessons learned and defending actions during schedule forensics.

    • ✗ To replace the need for a formal configuration management plan.

      Notes are a component of the plan, not a substitute for the overall procedures for tracking and traceability.

    • ✗ To store the personal contact information of the project team members.

      Schedule logs should focus on technical and procedural data relevant to the schedule model's execution.

    • ✗ To automatically calculate the Earned Value of the activity.

      Earned Value is a calculated numeric field; notes are qualitative data fields used for documentation.

18. 18 A scheduler uses a 120-day baseline. At day 60, $PV$ is 60 days and $EV$ is 45 days. What is the $SPI$ and what does it tell us?

    Divide the value earned by the value that was planned for that time period.

    $SPI = 0.75$; the project is accomplishing 75% of the planned work.

    $SPI$ is $EV / PV$ ($45 / 60 = 0.75$), indicating a significant inefficiency in schedule execution.

    • ✗ $SPI = 1.33$; the project is ahead of schedule.

      This results from dividing $PV$ by $EV$, which is the incorrect formula for an efficiency index.

    • ✗ $SPI = 0.75$; the project is under budget by 25%.

      $SPI$ relates to schedule progress; budget performance is measured by the $CPI$.

    • ✗ $SPI = -15$; the project is 15 days behind schedule.

      This is the Schedule Variance ($SV$), not the Performance Index ($SPI$).

19. 19 Why is it discouraged to rely solely on a scheduling tool to resolve Out-of-Sequence ($OOS$) logic?

    Consider the role of human expertise in validating project dependencies.

    Only the project team can determine if the original logic was incorrect or needs adjustment.

    Tools apply algorithms (like retained logic), but human judgment is needed to decide if a dependency should be removed or decomposed.

    • ✗ Tools are unable to calculate dates once $OOS$ logic is introduced.

      Tools will still calculate dates using specific overrides, but the results may not be valid for project management.

    • ✗ The tool will automatically delete the predecessor activity to fix the error.

      Software does not delete user data; it simply flags the violation of assigned logical relationships.

    • ✗ Manual resolution is required by PMI to maintain certification status.

      This is a best practice for model integrity, not a regulatory requirement for individual certification.

20. 20 What is the primary difference between 'Schedule Variance ($SV$)' and 'Schedule Variance in Time ($SV(t)$)'?

    Look at the unit of measurement used in the two different management methodologies.

    $SV$ is measured in monetary units, while $SV(t)$ is measured in time units.

    EVM traditionally uses cost-based values for schedule metrics, whereas ESM provides a variance expressed directly in days or months.

    • ✗ $SV$ measures cost overruns, while $SV(t)$ measures schedule delays.

      $SV$ and $SV(t)$ are both schedule metrics; cost overruns are measured by $CV$ (Cost Variance).

    • ✗ $SV$ is used for predictive projects, while $SV(t)$ is only used for Agile projects.

      Both are applicable to predictive models to enhance the accuracy of timeline tracking and forecasting.

    • ✗ $SV$ is a ratio, while $SV(t)$ is an absolute number.

      Both variances are absolute values (subtraction); their corresponding indices ($SPI$ and $SPI(t)$) are the ratios.

21. 21 You are auditing a subcontractor's schedule and find a task with a 20-day lag between two finish-to-start activities. Why is this considered a risk?

    Think about the visibility of uncertainty in 'invisible' time delays.

    Risk can consume or extend fixed lags with unanticipated consequences to duration.

    Lags are 'hidden' time; it is better to model them as discrete activities to track their specific risks and uncertainties.

    • ✗ Lags automatically create negative float in the network.

      Lags delay successors but only create negative float if the delay exceeds the available project time.

    • ✗ Lags are forbidden by the Practice Standard for Scheduling.

      Lags are allowed but should be used sparingly and modeled as activities whenever possible.

    • ✗ A lag increases the $SPI$ of the project artificially.

      Lags do not earn value ($EV$); they only affect the timing of when future work can be started ($PV$).

22. 22 If a project has an $SPI < 1.0$ and a $CPI > 1.0$, what is the most likely status of the project?

    Interpret the meaning of a value less than one and a value greater than one in performance ratios.

    Behind schedule but under budget.

    The schedule index indicates inefficiency ($<1.0$), while the cost index indicates efficiency ($>1.0$).

    • ✗ Ahead of schedule but over budget.

      This would require an $SPI > 1.0$ and a $CPI < 1.0$.

    • ✗ Behind schedule and over budget.

      This would require both the $SPI$ and the $CPI$ to be less than 1.0.

    • ✗ Ahead of schedule and under budget.

      This would require both efficiency indices to be greater than 1.0.

23. 23 A scheduler identifies 'Near-Critical Paths' during the monitoring phase. Why is this a 'high-difficulty' monitoring task?

    Consider the risk of non-critical activities delaying the project.

    Paths with minimal float are susceptible to becoming the critical path with slight perturbations.

    Vigilant monitoring is required because a small delay on a near-critical path can shift the entire project's completion date.

    • ✗ Near-critical paths are required by law to have their own $SPI$ calculation.

      Indices are usually calculated at the project or work package level, not for every specific logical path.

    • ✗ The critical path method assumes only one path can ever exist.

      Projects often have multiple paths, including several that are critical or nearly critical.

    • ✗ Near-critical paths do not contain any Earned Value.

      All activities in the WBS that are in the schedule model have planned and earned value.

24. 24 What happens to the $SPI$ as a project reaches 100% completion?

    Think about the behavior of a ratio when the numerator and denominator finally become equal.

    It will inevitably move toward 1.0, losing its predictive value.

    As $EV$ eventually equals $PV$ at the end of a project, the $SPI$ becomes 1.0 even if the project finished very late.

    • ✗ It becomes the best indicator of the project's final time delay.

      Traditional $SPI$ fails to show late completion; time-based metrics like $SPI(t)$ are needed for that purpose.

    • ✗ It drops to $0.0$ once the final activity is archived.

      The index converges to 1.0 because all planned work has finally been earned.

    • ✗ It is replaced by the $CPI$ as the only valid metric.

      While cost performance remains important, schedule performance tracking at completion uses actual finish dates versus baseline.

25. 25 When monitoring subcontractor performance, which document provides the governance and approval workflows for schedule changes?

    Identify the functional plan that sets the rules for the scheduling professional's daily work.

    Schedule Management Plan

    This plan defines the tools, thresholds, and processes used for controlling and updating the schedule model.

    • ✗ Project Charter

      The charter provides high-level authorization but does not contain detailed procedural workflows for scheduling.

    • ✗ Risk Register

      The register lists specific threats and opportunities, not the overarching governance for the schedule tool.

    • ✗ Issue Log

      The log records current problems, whereas the management plan dictates how to handle changes to the plan.