What is earned value?

EVM is a technique to monitor/track projects. EVM has 2 important index statistics: CPI and SPI.

CPI is the cost performance index, and if it's >= 1 it means that the project is OK with the budget, if it's < 1, it means that the project is over-budget.

SPI is the schedule performance index, and if it's >=1 it means that the project is on schedule or ahead of schedule, if it < 1, it means that the project is behind schedule.