Earned value is simple arithmetic on three numbers: planned value, earned value and actual cost. The arithmetic rarely breaks. The inputs do. When progress is assessed by feel one week, by quantities the next, and by “almost done” when a milestone is under pressure, SPI and CPI stop measuring performance. They measure the storytelling.
Consistent progress measurement is the control that makes EV useful. Without it, dashboards still look professional. They are just not comparable to last period.
Where inconsistent progress enters the file
- Activities marked complete while punch lists, tests or documentation remain.
- Rules switched from units to percent because units were hard to count.
- Optimistic jumps before a board pack, reversed the following month.
- Different packages using different done criteria for the same activity type.
- Cost closed on a different cut-off from the schedule progress.
Why SPI and CPI then mislead
SPI rises when earned value rises faster than the plan. If earned value rose because the rule softened, schedule performance did not improve—the definition of progress did. CPI does the same with cost. Leadership then debates a recovery that never happened, or ignores a bleed that the index temporarily hid.
| Inconsistent practice | What EV reports | What is true |
|---|---|---|
| Soft completes | SPI improves | Successors unlock early in software only |
| Rule change mid-job | Trend break | Measurement changed, not productivity |
| Late progress dump | One-period surge | Catch-up of reporting, not work |
| Cost on another week | CPI swings | Numerator and denominator disagree |
| Package-specific rules | No project SPI | Four local truths |
Rules that keep EV honest
- Write the progress method by activity type before the first update.
- Freeze the method for the life of the baseline unless change control says otherwise.
- Tie “complete” to objective criteria the baseline assumed.
- Use one data date for schedule progress and actual cost.
- Explain any method change in the same paragraph as the index movement.
What directors should ask every period
Ask how progress was measured. Ask whether that method matches last period. Ask whether any activity is complete without its done criteria. If those answers are vague, do not argue about SPI yet. Fix the measure.
EV still needs a sound network
Consistent progress on a broken schedule only produces consistent nonsense. Logic, calendars and remaining duration still matter. EV sits on top of a maintainable programme; it does not replace one.
EVM Solutions sets progress rules with the baseline, then runs earned value and the narrative on the same data date. If your SPI moves every month while the site story barely changes, send the progress rules and the last three updates. The failure is usually in the measure—not in the formula.
