Why this article exists (before we look at any charts)
In the System Baseline edition of The Ocean Carrier Reliability Illusion, we established a simple but critical shift:
Vessel schedule reliability doesn’t break at arrival.
It breaks inside the cargo receiving window.
That window - defined by the Earliest Return Date (ERD) and the CY Cutoff - is where export execution actually happens.
This edition applies the same framework to ONE, a carrier whose alliance-heavy network and port mix produce a distinct execution profile once you look beyond arrival times.
All terms used here are defined in the Reliability Series - Methodology Appendix:
https://www.tradelanes.co/blog/reliability-series-methodology-appendix
Data scope (ONE sample)
This analysis is based on an observational system sample of executable export port-calls and is not a statistically randomized sample.
- Port-calls: 1,004
- Vessels: 149
- Ports: 8
- Carrier: ONE (ONEY)
Filters applied:
- ERD and CY Cutoff both required
- Drift >40 days treated as data error and excluded
Section 1 - How often do ONE receiving windows actually move?
A receiving window is considered moved if either ERD or CY Cutoff shifts by one calendar day or more.
Figure 1 - Receiving Window Stability (ONE)
- Stable receiving windows: 51.79%
- Moved receiving windows: 48.21%
Plain-English meaning:
ONE receiving windows are stable in a slim majority of port-calls - but nearly half still move. That is more than enough movement to create routine execution breaks even when arrival reliability appears strong.
Section 2 - Drift isn’t chaos; it has a shape
Drift measures how far ERDs or CY Cutoffs move between original and final values.
Figure 2 - ERD Drift Distribution (ONE)
- 0-1 day: 62.85%
- 1-2 days: 8.76%
- 2-3 days: 4.88%
- 3+ days: 23.51%
Plain-English meaning:
Most ONE ERD changes are small - but nearly one in four port-calls experience 3+ days of ERD drift.
Static buffers are built for the middle of the curve.
Operational pain lives in the tail.
Section 3 - CY cutoffs are where risk concentrates for ONE
Across the ONE sample, CY Cutoff drift exceeds ERD drift.
Figure 3 - ERD vs CY Drift (ONE)
Average drift
- Mean ERD drift: 1.72 days
- Mean CY drift: 1.94 days
Threshold comparison
- ≥1 day drift: ERD 37.15% vs CY 40.64%
- ≥2 days drift: ERD 28.39% vs CY 31.08%
- ≥3 days drift: ERD 23.51% vs CY 26.20%
Plain-English meaning:
For ONE, as with the system baseline, CY Cutoffs remain the dominant execution constraint. ERDs may look manageable early, but CY behavior ultimately determines whether plans still fit.
Section 4 - Timing matters more than averages
A late-stage change occurs within the final 72 hours before the receiving window opens.
Figure 4 - Late-Stage Receiving Window Changes (ONE)
- ERD changed in last 72 hours: 29.18%
- CY Cutoff changed in last 72 hours: 26.69%
Plain-English meaning:
Late-stage changes are common in the ONE sample. In practice, this explains why execution issues often surface after plans feel locked.
So far, we’ve looked at how windows move.
Next, we look at where.
Section 5 - Volatility is not evenly distributed across terminals (ONE)
The Port Volatility Index (PVI) reflects how quickly static planning assumptions break at a port.
Figure 5 - Port-Level Drift (ONE)
Below are the highest-volatility ports in the ONE sample. Ports with small sample sizes should be interpreted cautiously.
USTIW (PVI 10.0)
- Mean ERD drift: 3.12 days
- Mean CY drift: 3.35 days
- Stable window rate: 23.65%
- ERD late-stage change: 66.50%
What this feels like:
This is a high-movement environment. Plans can break early and often, and buffers need range, not precision.
USORF (PVI 8.9)
- Mean ERD drift: 3.25 days
- Mean CY drift: 3.02 days
- Stable window rate: 15.73%
- CY late-stage change: 34.83%
What this feels like:
Frequent re-validation. Reliability stress comes from frequency, not isolated spikes.
USSAV (PVI 8.0)
- Mean ERD drift: 2.63 days
- Mean CY drift: 2.93 days
- Stable window rate: 23.66%
What this feels like:
Movement is expected and meaningful. Static assumptions erode quickly.
USNYC (PVI 7.3)
- Mean ERD drift: 2.22 days
- Mean CY drift: 2.86 days
- Stable window rate: 37.98%
What this feels like:
Moderate drift, but enough late movement to disrupt otherwise workable plans.
USLAX / USOAK (Lower PVI)
- Mean drift under 1 day
- Stable window rates above 75%
What this feels like:
More forgiving environments - but still subject to late-stage CY movement.
Section 6 - Severity still exists, even when averages look manageable
Figure 6 - Top 10 Highest-Severity ONE Events
Top examples:
- ONE CYGNUS (USNYC): ERD 13d, CY 26d, late-stage 1, score 40
- YM MUTUALITY (USTIW): ERD 20d, CY 14d, late-stage 2, score 36
- HYUNDAI SUPREME (USTIW): ERD 14d, CY 17d, late-stage 2, score 33
Plain-English meaning:
These are stress tests, not typical shipments. They show how quickly drift can stack when multiple changes coincide.
Static buffers fail in these scenarios by design.
Section 7 - The KPI that matters for ONE
Figure 7 - Receiving Window Movement Rate (ONE)
- Moved receiving windows: 48.21%
- Stable receiving windows: 51.79%
- Scope: 1,004 port-calls • 149 vessels • 8 ports
Plain-English meaning:
For ONE exports, predictability must be actively managed. Arrival performance alone does not prevent execution breaks.
Section 8 - Why static buffers fail (and why this repeats)
Figure 8 - Static Buffer vs Dynamic Time Buffer (DTB)
Plain-English meaning:
When drift has a long tail and late-stage changes are common, fixed buffers are routinely exceeded. Planning must adapt to observed behavior, not assumptions.
Before we move to the next carrier
A vessel can be “on time” and still break export execution if the receiving window shifts underneath it.
This ONE edition shows:
- stability is the majority state, but movement is still frequent,
- CY Cutoff behavior remains the primary execution risk, and
- volatility concentrates by port, not evenly across the network.
Next in the Carrier Reliability Series:
Evergreen - publishing soon.
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