# Service performance review memorandum

## Priority

Review Harbour express (18/18) and Harbour standard (14/37) first, along with Eastgate express (26/37). Southbay express has only four mature orders and one late order. Collect more data before treating its 25% rate as stable.

| Hub | Raw late rate | Standardized late rate |
| --- | --- | --- |
| Eastgate | 56.36% | 49.02% |
| Southbay | 21.88% | More data needed |
| Harbour | 58.18% | 68.92% |
| Westhill | 36.36% | 38.64% |

## Method

For each hub/service cell, late_rate = late/eligible and gap_pp = (late_rate - 0.10) * 100. Apply the sample check before thresholds. A gap exactly at 15 points is Review needed, not Priority review. A gap exactly at 5 points is Within threshold.

Standardized rate = 0.5 * standard rate + 0.5 * express rate. Eastgate express accounts for 37/55 mature orders. Its raw 56.36% rate becomes 49.02% at equal weights. Harbour express accounts for only 18/55, so its standardized rate rises from 58.18% to 68.92%. Overall differences partly reflect service mix and should not be attributed entirely to hub performance.

## Next evidence

Southbay express needs at least 11 more mature orders to reach the operational threshold of 15; the added observations can change its rate. Hold the observation period and cohort rules consistent, retaining cancelled and not-mature records. Fifteen is a review threshold, not proof of statistical significance.

Weather, route distance, customer appointments and shift schedules are absent. This comparison does not establish individual responsibility, unfair treatment or an improvement forecast. Inspect Harbour express handovers and departures, then compare like routes, services and time periods before designing a process experiment.