PMP® Schedule Variance (SV): How to Calculate and Analyze SV
One of a project manager’s many critical roles is to keep projects on track. It can be easy for projects to deviate from the agreed-upon schedule. While this may happen for reasons out of anyone’s control, schedule variances are often unnecessary or preventable. Ultimately, all schedule variances can impact the project’s budget, as well as many other critical success factors. Regularly analyzing schedule variance is a helpful way to ensure your project stays on track and keep schedule variances to a minimum. For this reason, schedule variance is a concept potential PMP credential holders should be familiar with for the PMP exam.
Your Project Management Academy experts have put together this schedule variance guide as you prepare for the PMP exam. If you have any other questions, feel free to let us know.
On this page:
Defining Schedule Variance
Schedule variance (SV) for the PMP exam is a crucial component of Earned Value Management (EVM), a technique for measuring project progress across the scope, cost, and schedule categories. Besides SV, EVM includes analyses of cost performance, schedule performance, and cost variance.
Potential PMP credential holders should be aware of the following types of schedule variances:
- Point-in-time schedule variance is also known as period-by-period schedule variance. It considers the SV during a single, specific period of the project.
- Cumulative schedule variance describes the total SV over several consecutive periods.
The role of schedule variance is to determine how ahead of or behind schedule you are. This knowledge helps project managers with essential tasks such as catching problems quickly or deciding how best to distribute the remaining project resources during the rest of the project.
Schedule Variance Formula PMP
As with the other EVM analyses, schedule variance considers both the planned project work and the actual work completed. Specifically, SV equals the difference between your project’s earned value and planned value.
SV = EV – PV
Earned value (EV) describes the value in dollars of any work completed so far. Another term for EV is Budgeted Cost of Work Performed (BCWP). You can calculate EV by multiplying the percentage of work done by the budget at completion (BAC). For example, if you have completed 75% of a $1,000 project, your EV is $750.
EV = (% completed work) * (BAC)
Planned value (PV) describes the value in dollars of any work scheduled to be completed. Another term for PV is Budgeted Cost of Work Scheduled (BCWS). You can calculate PV by multiplying the percentage of scheduled work by the budget at completion (BAC). For example, if you planned to be 50% done with a $1,000 project by Day Five, your PV is $500.
PV = (% scheduled work) * (BAC)
Budget at completion (BAC) is the agreed-upon or approved total spending for the project. BAC is typically determined based on project estimates for every part of the work breakdown structure established at the start of a project, but it can be changed as the project progresses using the project’s approved change control procedures.
You may see the SV formula written as SV = BCWP – BCWS. This formula’s only difference is in the terminology used, not in the actual calculation being done.
Interpreting schedule variance results
The result of your calculations using the PMP schedule variance formula should be a single number greater than, less than, or equal to zero. You should interpret your results as follows:
- A positive SV indicates your project is ahead of schedule.
- A negative SV indicates your project is behind schedule.
- An SV equalling 0 indicates your project is on schedule.
Your schedule variance at the end of your project will be zero because 100% of the planned value will have been earned.
SV formula PMP example
The PMP exam may provide a hypothetical situation and ask PMP exam applicants to calculate and interpret SV based on the given information.
For example, let’s say you have a construction project and plan to do 20% of the work each week. The project is scheduled to take five weeks and costs $80,000 in total. After three weeks, 50% of the work has been completed, and $50,000 has been spent. Is your project ahead of or behind schedule?
In this example, you have the following information:
- BAC = $80,000
- EV = (50%) * ($80,000) = $40,000
- PV = (60%) * ($80,000) = $48,000
- AC = $50,000
Using the schedule variance formula, you can find the SV = $40,000–48,000 = –$8,000. A negative SV means your project is behind schedule.
Here’s a tip: carefully consider which information you need to correctly answer questions on the PMP exam! This hypothetical question included extraneous information about the project’s actual cost (AC). Accidentally using the AC instead of other values in the equation can give you the wrong answer.
Related SV Methods
There are a few other formulas closely related to SV you should familiarize yourself with for the PMP exam. Review these concepts below, and make sure to reach out to your Project Management Academy experts with any questions.
Cost variance (CV): definition/results
Cost variance (CV) is a form of variance analysis that measures project progress against the project’s cost baseline. This PMP exam concept looks at the project’s earned value (EV) and actual cost (AC). AC describes the amount spent so far on the project, also known as the actual cost of work performed (ACWP). CV uses the following formula:
CV = EV – AC
A positive CV means you are under budget, while a negative CV indicates you are under budget. Learn more about cost variance in our CV PMP Exam Guide.
Schedule variance percentage (SV%): definition/results
Schedule variance percentage (SV%) is a performance metric that expresses, as a percentage, how much a project is deviating from its schedule. SV% uses the following formula:
Or, in simpler terms, SV% = SV/PV. A positive SV% indicates your project is ahead of schedule, while a negative SV% indicates your project is behind schedule, and an SV% of zero indicates your project is precisely on schedule.
Schedule performance indicator (SPI): definition/results
A schedule performance indicator (SPI) is a project efficiency rating that expresses in a percentage how efficiently you have used your project time resources so far. SPI uses the following formula:
An SPI value greater than or equal to 1 (≥ 100%) indicates the time allocated to your project has been used efficiently. An SPI value less than 1 (<100%) indicates your use of project time resources may need to be more efficient.
To complete schedule performance indicator (TSPI): definition/results
Another project efficiency rating is the To Complete Schedule Performance Indicator (TSPI). While SPI looks back at how you have used your project resources so far, TSPI looks ahead to see how remaining project time should be used. TSPI uses the following formula:
A TSPI value greater than or equal to 1 (≥ 100%) indicates you can be lenient with your remaining project time. A TSPI value less than 1 (<100%) indicates you need to use your remaining time more efficiently.
Schedule Variance and the PMP Exam
As you prepare to take the PMP exam, the most important things for you to know about schedule variance include:
- The definition of schedule variance
- The SV formula
- Which variables to use in your SV calculations
- How to interpret the results of your SV calculations – in other words, what does SV tell you about your project?
Of course, it’s helpful to understand the big picture of how the schedule variance fits into project management in general. Calculating schedule variance using the SV formula provides metrics that help you assess how well you are managing your project schedule and resources.
Beyond the PMP exam, however, the SV formula is not the only component of planning and following a project schedule. Here are a few things to keep in mind as you calculate and assess schedule variance for real-life projects:
- Calculate a baseline schedule during the project planning process to provide a reference as you assess project schedule variance.
- Keep an eye out for scheduling conflicts and any potential constraints or blockers.
- Remember a SV may have associated cost variances or other issues. For example, being ahead of schedule is usually not worth sacrificing quality.
- Double-check your SV calculations to ensure you are using the correct numbers.
- Remember, calculating SV and other variances requires some degree of estimating values. Consider potential issues such as inaccurate estimates or bias that may affect your results.
Schedule variance is an essential concept in project management, and potential PMP credential holders should be prepared to answer at least a few questions on this subject for the PMP exam.
Studying for the PMP Exam?
Schedule Variance PMP Summary
Let’s review your SV essentials for the PMP exam.
Schedule variance is part of Earned Value Management and helps project managers determine if a project is ahead of or behind schedule and by how much. To calculate SV, subtract your project’s planned value (PV) from its earned value (EV): SV = EV – PV. You will also need to know the value of your project’s planned budget at completion (BAC).
If your SV is positive, your project is ahead of schedule. If it is negative, your project is behind schedule. An SV of 0 indicates your project is precisely on schedule.
Was this guide helpful to understanding schedule variance for the PMP Exam? Our experts are here to help you master this concept and other essential knowledge to pass the exam on your first try. Take a look at the PMP Certification Training courses we offer, and as always, let us know if there is anything else we can do to help.
Upcoming PMP Certification Training – Live & Online Classes