Schedule Variance is a quantitative value utilized by the project managers to characterize schedule performance while the project is still in process, or after it is completed. This is the completed work compared against the planned schedule. Schedule Variance (SV) can be calculated as the difference between the Earned Value (EV) and the Planned Value (PV): EV – PV = SV, so a positive value of SV means that your project is ahead of schedule, while a negative one points the schedule delay.
The EV stands for amount of time spent to reach the current level of progress on the project, while the PV stands for the time which reaching the project’s current state should have taken according to the project plan. To determine Schedule Variance Rate (as a percentage) you may use the following formula: ((Earned Value - Planned Value)/Planned Value) x 100.