Calculate the schedule performance index (SPI = EV ÷ PV) from earned value and planned value, with schedule variance, plus CPI when you add actual cost.

Budgeted value of work performed, not actual cost.

Budgeted value of work scheduled by the same status date, in the same currency and scale as EV.

Cost performance (CPI)
Adds the cost performance index CPI = EV ÷ AC and cost variance CV = EV − AC.

Related Calculators

Schedule Performance Index Formula

SPI = EV / PV

Variables:

  • SPI is the Schedule Performance Index (EV/PV)
  • EV is earned value: the budgeted value of work performed, not actual cost
  • PV is planned value: the budgeted value of work scheduled by the status date

To calculate Schedule Performance Index, divide the earned value by the planned value.

How to Calculate Schedule Performance Index?

The following steps outline how to calculate the Schedule Performance Index.

  1. First, determine the earned value. 
  2. Next, determine the planned value. 
  3. Next, gather the formula from above: SPI = EV / PV.
  4. Finally, calculate the Schedule Performance Index.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

earned value = 300

planned value = 200. SPI = 300 / 200 = 1.5, or 150% schedule efficiency. SV = 300 − 200 = +100 in the same value units. More budgeted work value has been earned than planned at the status date; this does not forecast the completion date.

FAQs about Schedule Performance Index

What is Earned Value Management (EVM)?

Earned Value Management (EVM) is a project management technique for measuring project performance and progress in an objective manner. It integrates project scope, cost, and schedule measures to help the project management team assess and measure the project performance and progress.

Why is the Schedule Performance Index (SPI) important?

SPI compares budgeted work performed with budgeted work scheduled at the same status date. It helps assess earned-value schedule performance, but does not measure calendar days ahead or behind or predict completion.

Can SPI be greater than 1?

Yes. SPI > 1 means EV > PV; SPI = 1 means EV = PV; SPI < 1 means EV < PV at the status date. These compare budgeted work values, not completion dates. SPI can return to 1 at project completion even if the project finishes late.

How does SPI relate to other project management metrics?

SPI = EV / PV measures earned-value schedule performance. CPI = EV / AC compares earned value with actual cost (AC) and measures cost efficiency; enter actual cost under Cost performance (CPI) to calculate it. Schedule variance is SV = EV − PV, expressed in the same money or value units as EV and PV, not in days.