The Progress Update That Hid a Slipping Path
At the end of month 6 of a 12-month bridge rehabilitation, the schedule update shows: planned value (BCWS) $4.2M, earned value (BCWS of work performed) $3.6M, actual cost $3.9M. The project manager reports SPI = 0.86 and states the project is "behind but recoverable" because the critical path activities-girder fabrication and deck replacement-show only 5 days of slippage against a 20-day float on the schedule summary. However, the scheduler notices that girder fabrication, originally scheduled to finish month 7, now has a forecast finish in month 9, and deck replacement cannot start until girders arrive. Two change orders added scope worth $300k that were not in the baseline. The PM wants to report the 5-day slippage as the headline status.
1. Assess the PM's reported status. What does the evidence actually indicate about schedule health, and what should the report say?
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The PM's headline is misleading on three counts.
Float is being misread. Girder fabrication was forecast to finish month 7; it now forecasts month 9-a 2-month slip, not 5 days. The "5 days slippage" appears to be measured against a summary bar or against the wrong baseline. The 20-day float belongs to a summary line, not to the driving activity. When the driving activity's forecast finish moves 60 days, the project finish moves unless downstream float absorbs it-and deck replacement cannot start until girders arrive, so it cannot.
The critical path has shifted. Girder fabrication → deck replacement is now the driving path. The report must show the new critical path and its total float (likely negative or near zero), not the stale baseline float.
Earned value alone understates the problem. SPI = 3.6/4.2 = 0.86 looks "behind but recoverable," but EV aggregates across activities; a healthy early phase can mask a failing critical activity. Also, $300k of added scope is not in the baseline-comparing EV to the old BCWS distorts SPI. The baseline should be re-baselined (or a separate change-order baseline tracked) so performance is measured against current scope.
What the report should say: Girder fabrication is the driving activity, forecasting a 60-day slip; deck replacement start is at risk; project completion is forecast to move unless recovery is applied. Report the new critical path, forecast completion date, and the recovery plan-not a 5-day summary slip.
2. What corrective and reporting actions should the scheduler recommend?
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Corrective (schedule):
- Recover girder fabrication: expedite the fabricator, add a second production line, or re-sequence deck work to start in zones where girders are already delivered (partial start-to-start overlap). Quantify days recovered vs. cost.
- Re-baseline or track change orders separately so the $300k of added scope is reflected; otherwise SPI will keep misrepresenting performance.
- Recompute the critical path and total float after recovery and identify new near-critical paths.
Reporting:
- Report forecast completion date and variance, not just SPI/CPI.
- Show a critical path narrative naming the driving activities and their forecast finishes.
- Present EVM against the current baseline (or dual baseline: original + approved changes).
- Flag the float-consuming activities explicitly so management sees the buffer is being spent.
- State the recovery plan, owner, and decision date-a status report without an action is just a scoreboard.
Judgment point: the exam tests whether you catch that summary-level float and aggregate SPI can both look benign while the driving path is failing. Trust the activity-level forecast, not the summary number.