1. What is Performance Index?

Performance Index (PI) is a project management metric that measures schedule performance efficiency. It calculates the ratio of earned value to planned value, providing insight into how efficiently project work is being performed compared to the planned schedule.

2. How Does the Calculator Work?

The calculator uses the Performance Index formula:

Where:

• \( PI \) — Performance Index (dimensionless ratio)
• \( EV \) — Earned Value (actual work completed)
• \( PV \) — Planned Value (work scheduled to be completed)

Interpretation:

• PI > 1.0: Project is ahead of schedule
• PI = 1.0: Project is on schedule
• PI < 1.0: Project is behind schedule

3. Importance of Performance Index Calculation

Details: Performance Index is crucial for project monitoring and control. It helps project managers identify schedule variances early, make informed decisions about resource allocation, and take corrective actions to keep projects on track.

4. Using the Calculator

Tips: Enter earned value and planned value in consistent units (dollars, hours, work units). Both values must be positive numbers, with planned value greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between SPI and CPI?
A: SPI (Schedule Performance Index) measures schedule efficiency (EV/PV), while CPI (Cost Performance Index) measures cost efficiency (EV/AC).

Q2: How often should PI be calculated?
A: PI should be calculated regularly throughout the project lifecycle, typically during weekly or monthly project status reviews.

Q3: What is a good Performance Index value?
A: A PI of 1.0 indicates perfect schedule performance. Values above 1.0 are generally desirable, though extremely high values may indicate overly conservative planning.

Q4: Can PI be negative?
A: No, since both EV and PV are positive values, PI will always be a positive number. A value of 0 indicates no work has been completed.

Q5: How does PI relate to project forecasting?
A: PI is used in earned value management to forecast project completion dates and estimate time to complete remaining work.