Cost/Schedule Control – weekly and cumulative SPI (alternate)
Remember the guidelines on when to consider changing the baseline (PV): 25% to 40% into the project? The statistical information for those guidelines comes from SPI data on medium to high risk projects. The chart on this page shows weekly and cumulative SPI (alternate) for a low risk project. Notice how the cumulative SPI (alternate) stabilizes after about 15% complete? This example stabilized more quickly than medium to high risk projects.