Progress Measurement, Performance Analysis, and Forecasting
This domain tests how progress is measured, how schedule performance is analyzed, and how completion is forecast. CAPES expects you to distinguish duration percent complete from physical or earned progress, use earned schedule where appropriate, and explain why a favorable cost-based schedule indicator can coexist with a late critical path.
Measurement and forecasting rules
- Percent complete methods include duration, units completed, milestones, and physical measurement. The method must match the work type and be stated in the schedule basis.
- Earned schedule (ES) converts EV into the planned time at which that EV should have been earned. SPI(t) = ES / actual time; IEAC(t) = planned duration / SPI(t).
- Traditional SPI = EV / PV is a cost-based schedule indicator and can mislead near the end of a project.
- Critical path progress matters: non-critical work can earn value while the critical path slips.
- Forecasts should use trend data and remaining work, not just a single period.
Worked example
A project has a planned duration of 10 months and linear planned value. At month 5, PV is 50% and EV is 40%. Earned schedule maps 40% EV to month 4 of the plan, so ES = 4 months. SPI(t) = 4 / 5 = 0.80. IEAC(t) = 10 / 0.80 = 12.5 months. Traditional SPI = 40% / 50% = 0.80 as well in this linear case, but the earned-schedule forecast gives a time-based completion estimate. If the critical path has consumed all float, the 12.5-month forecast may be optimistic without recovery action.
Traps that cost marks
Using duration percent complete for a long activity that is 90% complete but has months of testing left; reading SPI greater than 1 as proof of early completion when the critical path is late; and forecasting from cumulative EV without remaining-work analysis. Also, changing the measurement method mid-project breaks comparability unless the baseline is adjusted through change control.