VoltSim builds a regression model to predict electric scooter battery degradation so fleet operators can schedule maintenance. The issue is that only 58% of scooters have complete lab-test discharge curves, while the rest have partial field telemetry with missing temperature and load measurements.
| Metric | Complete-data validation set | Incomplete-data validation set | Change |
|---|---|---|---|
| RMSE (cycles to 80% capacity) | 18.4 | 34.7 | +88.6% |
| MAE (cycles) | 12.1 | 24.9 | +105.8% |
| R² | 0.81 | 0.52 | -0.29 |
| Calibration slope | 0.97 | 0.71 | -0.26 |
| % predictions within ±20 cycles | 84% | 61% | -23 pts |
| Mean prediction bias | -1.8 cycles | -14.6 cycles | More underprediction |
Leadership wants to use the model for maintenance planning across the full fleet, but performance degrades sharply when validation relies on incomplete data. You need to determine whether the current validation approach is trustworthy and how to validate the model when experimental or simulation data is missing or only partially observed.