Schedule Variance Calculator

Schedule variance (SV) is the earned value measure of schedule performance. It compares the value of work actually completed (Earned Value, EV) with the value of work that should have been completed by now according to the baseline (Planned Value, PV). A negative SV means you are behind schedule; a positive SV means you are ahead.

How to use the calculator

1. Enter the Planned Value for the status date.
2. Enter the Earned Value for the same date.
3. Read SV, SV percentage and the Schedule Performance Index (SPI).

Formulas

• SV = EV - PV
• SV% = SV / PV × 100
• SPI = EV / PV

Worked example

By the end of month 5, the baseline planned work worth 1,200,000 (PV). Progress measurement shows work worth 1,020,000 has been completed (EV). SV = 1,020,000 - 1,200,000 = -180,000, SV% = -15% and SPI = 0.85. The project has accomplished 85% of the work planned to date.

Limitations of SV

• SV is in money, not time. It tells you how much planned work is missing, not how many days late you are. Use earned schedule (ES) or the critical path to estimate time delays.
• SV always returns to zero at completion. When all work is done, EV equals PV equals BAC, so SV becomes zero even if the project finished months late. SPI similarly drifts back to 1.0 in the final stages.
• Critical path matters. A positive SV can hide delays on critical activities if non-critical work is ahead.

What to do with a negative SV

Find which work packages are behind, check whether they are on the critical path, and plan recovery: more resources, overtime, resequencing or scope changes.