Earned Value Performance Index

This project management task calculates the Earned Value Cost Performance Index (CPI), a core metric in earned value management. It helps project managers assess cost efficiency objectively. A CPI below 1 signals cost overruns, while values above 1 indicate efficiency. The formula supports disciplined project control and executive reporting. When paired with schedule metrics, it provides a holistic performance view. This lightweight implementation allows teams to adopt EVM principles without expensive software tools.