Earned Value Management (EVM) compares planned value, earned value, and actual cost to calculate variance metrics and performance indices. Key measures include Schedule Variance (SV), Cost Variance (CV), Schedule Performance Index (SPI), and Cost Performance Index (CPI). EVM enables early detection of budget overruns and schedule delays, supporting corrective action. It requires disciplined planning and tracking but provides objective performance data. A defense contractor using EVM on a $200 million program identified a 0.85 CPI at month six, forecasting a $35 million overrun, triggering scope reduction negotiations with the client.