Introduction

In project management, maintaining control over the project schedule is crucial for delivering results on time and within budget. One of the key metrics used to assess schedule performance is Schedule Variance (SV). Understanding and effectively utilizing SV can help project managers identify deviations from the plan early and take corrective actions promptly.

This article provides an in-depth exploration of Schedule Variance, its calculation, interpretation, and relevance to the PMP exam—so you can apply it confidently in your career and on test day.

What Is Schedule Variance (SV)?

Schedule Variance (SV) is a metric used in Earned Value Management (EVM) that compares the amount of work actually completed (Earned Value) to the work planned (Planned Value). It indicates whether the project is ahead of or behind schedule in terms of budgeted work.

Unlike actual time delays, SV reflects progress in financial terms—so it’s a measure of performance against the plan, not clock time.

The Schedule Variance Formula

The formula for Schedule Variance is:

SV = EV – PV

Where:

• EV (Earned Value): The value of the work actually completed to date.
• PV (Planned Value): The value of the work that was planned to be completed by the same date.

Interpreting Schedule Variance Results

Schedule Variance helps you understand whether a project is ahead of or behind schedule:

• SV > 0: Project is ahead of schedule.
• SV = 0: Project is exactly on schedule.
• SV < 0: Project is behind schedule.

Important note: Since SV is based on budgeted value, it’s expressed in dollars (or your project’s unit of measure), not days or weeks.

Schedule Variance Example

Scenario: Your project has a total budget of $100,000 and is expected to take 10 weeks. After 5 weeks:

• Planned Value (PV): $50,000 (you planned to be halfway done)
• Earned Value (EV): $40,000 (you’ve only completed 40% of the work)

Now calculate:

SV = EV – PV = $40,000 – $50,000 = –$10,000

Interpretation: You are behind schedule. The value of the work completed is $10,000 less than planned.

Related Metrics in Schedule Analysis

Schedule Variance (SV) Percentage (SV%)

While SV gives you a dollar-based variance, SV% helps you understand how far off you are in relative terms. The formula is:

SV% = (SV / PV) × 100

Example: Using the earlier example where SV = –$10,000 and PV = $50,000:

SV% = (–10,000 / 50,000) × 100 = –20%

Interpretation: The project is 20% behind schedule, based on budgeted work.

Schedule Performance Index (SPI)

SPI is a ratio that shows how efficiently time is being used. The formula is:

SPI = EV / PV

Interpreting SPI:

• SPI > 1: Ahead of schedule
• SPI = 1: On schedule
• SPI < 1: Behind schedule

Using our example:

SPI = 40,000 / 50,000 = 0.8

Result: The project is operating at 80% schedule efficiency.

To-Complete Schedule Performance Index (TSPI)

TSPI estimates the schedule efficiency required to complete the project on time. It’s especially helpful when a project is in trouble and you need to know what it will take to recover. The formula is:

TSPI = (Total Budget – EV) / (Total Budget – PV)

Example:

• Total Budget = $100,000
• EV = $40,000
• PV = $50,000

TSPI = (100,000 – 40,000) / (100,000 – 50,000) = 60,000 / 50,000 = 1.2

Interpretation: You must work 20% more efficiently than originally planned to complete the project on time.

Conclusion: Why Schedule Variance (SV) Matters

Schedule Variance (SV) is more than just a formula—it’s a powerful lens for understanding whether your project is on track, ahead, or falling behind. As part of Earned Value Management, it gives project managers a standardized way to measure and communicate schedule performance using objective data.

For PMP exam success, it’s essential to not only memorize the SV formula but to know how and when to apply it. Practice interpreting SV, SPI, and TSPI in context so you’re prepared for both calculation-based and scenario-based questions.

In the real world, using SV as part of your regular project controls will help you manage risk, allocate resources more effectively, and avoid surprises that can derail your timeline.

Download Your Free PMP Exam Sample PDF

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• Schedule Variance (SV) and SPI practice questions
• Step-by-step explanations of calculations
• Scenario-based PMP-style questions
• Tips to avoid common estimating errors

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