Which metric is a direct measure of schedule efficiency in earned value management?

• A. Schedule Variance (SV)
• B. Cost Performance Index (CPI)
• C. Schedule Performance Index (SPI)
• D. Cost Variance (CV)

Answer: (C)

Schedule efficiency in earned value management is measured by the Schedule Performance Index, which is earned value divided by planned value. This ratio shows how effectively time is being used to deliver work. When the SPI is greater than 1, you’re earning more value than planned for the time spent, meaning you’re ahead of schedule; when it’s less than 1, you’re behind. The other metrics either reflect a difference between earned and planned value (schedule variance) or relate to cost (CPI, CV), and they don’t directly express how efficiently time is being converted into completed work. For example, with planned value 100 and earned value 110, SPI is 1.10 (ahead). With planned value 100 and earned value 90, SPI is 0.90 (behind).