CAPM Practice: Determine how to document project controls of predictive, plan-based projects

CPI = EV/AC measures cost efficiency — the value earned per dollar spent. CPI directly answers 'Are we getting our money's worth?' An CPI > 1.0 means efficient (getting more than $1 of value per $1 spent); CPI < 1.0 means inefficient (spending more than the value earned). CPI is the primary metric for cost performance monitoring.

**Why not B:** Schedule Performance Index (SPI) measures schedule efficiency (EV/PV), not cost efficiency. SPI tells you how efficiently the project is using time relative to the plan, which is a separate dimension from cost performance.

**Why not C:** Budget at Completion (BAC) is the total approved budget for the project. It is a static planned value, not a performance metric. BAC does not measure efficiency — it represents the original cost target against which performance is compared.

**Why not D:** Schedule Variance (SV = EV - PV) measures schedule performance in dollar terms, not cost efficiency. SV indicates whether the project is ahead or behind schedule, which is distinct from whether cost spending is efficient.