Schedule Variance in Earned Value Management
Schedule variance (SV) answers earned value vs planned value over time—not cost overruns. Use cost variance when the question is about budget dollars. Schedule Variance (SV) measures project timeline performance by comparing earned value to planned value. Unlike simple deadline tracking, SV provides a monetary view of schedule performance, enabling comparison across projects of different sizes.
Interpreting Schedule Variance
- SV > 0 (Positive): Ahead of schedule. More value earned than planned by this date.
- SV = 0: Exactly on schedule. Planned and actual progress align perfectly.
- SV < 0 (Negative): Behind schedule. Less work completed than planned.
SV Limitations and Best Practices
Schedule Variance has a known limitation: it always converges to zero at project end, regardless of how late the project finishes. For this reason, experienced project managers use SV alongside percent complete metrics and critical path analysis. The Schedule Performance Index (SPI) provides a ratio view that's often more intuitive for stakeholders.
Pro tip: Track SV weekly, visualize trends, and investigate root causes when SV drops below -5%.
Common schedule variance mistakes
- Mixing SV with SPI: Schedule variance is EV − PV; SPI is EV ÷ PV.
- Calendar vs work days: Align PV and EV to the same time unit (days or hours).
- Scope changes: Re-baseline PV when scope shifts or SV trends mislead.
The worked example for schedule variance was verified with the calculator form on this page—enter the same values to confirm the result.
Limitations: schedule variance results are estimates for learning and quick checks—not financial, legal, tax, or medical advice. Policies, grading scales, and local rules may differ; confirm outcomes with official sources before making decisions.
When to use this calculator
- Use this page when comparing earned value to planned value (schedule).
- Use SPI for the schedule performance index view.
- Use cost variance when the comparison is EV vs actual cost.
Still unsure about schedule variance percent? Start with the quick answer above, then open the linked calculator that matches your wording.
Comparison: when to use each method
Use this table to pick the right percent workflow before you calculate.
| Scenario | When to use |
|---|---|
| Percent of a number | Finding a part of a whole (tax, tip, score) |
| Percent change | Comparing old vs new values |
❓ Frequently Asked Questions
How do you interpret schedule variance (SV) in project tracking?
Schedule Variance = Earned Value - Planned Value. Positive SV means ahead of schedule.
How do I interpret schedule variance?
SV > 0: Ahead. SV = 0: On schedule. SV < 0: Behind schedule.
What is the relationship between SV and SPI?
SPI = EV / PV gives efficiency ratio. SV gives absolute variance.
🔍 Authoritative References
For more information about professional and project management calculations, consult these trusted sources:
- Project Management Institute - Project management standards and best practices
- OSHA - Workplace safety standards and guidelines
- ISO Standards - International quality and process standards