SPI (Schedule Performance Index)

This video explains how SPI is calculated, taking actual % complete and dividing it by planned % complete.

 

This is a measure of Schedule efficiency on a project. In other words, it is a ratio between what has been done and what should have been done by the current day. The calculation is Actual Project Percent Complete divided by Planned Project Percent Complete

What Does SPI Indicate?

  • SPI = 1.0 → The project is on schedule

  • SPI < 1.0 → The project is behind schedule

  • SPI > 1.0 → The project is ahead of schedule

SPI provides a quick snapshot of schedule health and helps identify if corrective action is needed.


How is SPI Calculated?

SmartPM calculates SPI using the following formula:

SPI = Earned Duration ÷ Planned Duration

  • Earned Duration: The amount of time that should have been spent to achieve the current level of progress.

  • Planned Duration: The amount of time that should have been used by now according to the baseline schedule.


Example-

If your project has:

  • Earned Duration = 60 days

  • Planned Duration = 75 days

Then:

SPI = 60 ÷ 75 = 0.80

This means the project is operating at 80% schedule efficiency and is behind schedule.


Why is SPI Important?

SPI helps project teams:

  • Monitor schedule health

  • Identify risks early

  • Make data-driven decisions to improve performance

By tracking SPI throughout the life of the project, you can ensure your team stays aligned and proactive.