In earned value management, which metric is used to gauge schedule performance?

In earned value management, which metric is used to gauge schedule performance?

• A. CPI, calculated as EV/AC.
• B. SPI, calculated as EV/PV.
• C. CV, calculated as EV-AC.
• D. SV, calculated as EV-PV.

Answer: (B)

The question is asking which metric in earned value management reflects how the project is performing on schedule. The Schedule Performance Index shows schedule performance by comparing what’s actually earned to what was planned to be earned, using EV divided by PV. If SPI is greater than 1, you’ve earned more value than planned and are ahead of schedule; if it’s less than 1, you’re behind; if it’s 1, you’re on track. This ratio is particularly useful because it normalizes progress across different project sizes, making it easier to compare performance over time or between projects. Other metrics focus on cost or absolute differences. For example, cost performance index (EV/AC) measures cost efficiency, not schedule. Schedule variance (EV−PV) shows the raw difference in value between earned and planned but doesn’t provide a normalized efficiency measure, which is why SPI is the preferred gauge of schedule performance.

The question is asking which metric in earned value management reflects how the project is performing on schedule. The Schedule Performance Index shows schedule performance by comparing what’s actually earned to what was planned to be earned, using EV divided by PV. If SPI is greater than 1, you’ve earned more value than planned and are ahead of schedule; if it’s less than 1, you’re behind; if it’s 1, you’re on track. This ratio is particularly useful because it normalizes progress across different project sizes, making it easier to compare performance over time or between projects.

Other metrics focus on cost or absolute differences. For example, cost performance index (EV/AC) measures cost efficiency, not schedule. Schedule variance (EV−PV) shows the raw difference in value between earned and planned but doesn’t provide a normalized efficiency measure, which is why SPI is the preferred gauge of schedule performance.