How to interpret SPI > 1?

SPI (Schedule Performance Index) is a measure of project schedule performance, calculated as the ratio of work performed to work planned at this point in time.

If SPI > 1, it means the project is progressing faster than planned. In other words, more work has been completed than expected at this point in time. This is a positive signal indicating ahead-of-schedule performance.

For example, if SPI = 1.2, it means that for every planned hour of work, 1.2 hours of work have been completed, indicating a good pace of project execution.