System Baseline Edition
Most discussions of ocean carrier reliability still revolve around a single question:
Did the vessel arrive on time?
That question is easy to measure.
It is also the wrong one for exporters.
Export execution happens inside the receiving window - the time period between the Earliest Return Date (ERD) and the CY Cutoff. That window determines whether cargo can actually gate in, whether trucks are dispatched correctly, and whether a booking makes the intended sailing.
When that window moves, exporters feel it immediately - even if the vessel still arrives “on time.”
All terms used in this article - including ERD, CY Cutoff, receiving window, drift, and late-stage change - are defined in the Reliability Series - Methodology Appendix:
https://www.tradelanes.co/blog/reliability-series-methodology-appendix
This article establishes the system baseline: how receiving-window reliability behaves across all carriers and terminals, after removing data errors and requiring both ERD and CY to be present.
Every carrier deep dive that follows applies this same framework at the 1,000-ft level.
The dataset represents an observational system sample of executable export port-calls and is not a statistically randomized sample.
Filters applied:
Full methodology, thresholds, and definitions are documented here:
https://www.tradelanes.co/blog/reliability-series-methodology-appendix
A receiving window is considered moved if either the ERD or CY Cutoff shifts by one calendar day or more from its originally published value.
That alone explains why exporters can feel constant friction even in periods when headline ‘on-time arrival’ metrics look healthy.
Plain-English meaning:
Even after removing obvious data errors, nearly half of export receiving windows moved at least once.
This is the reliability illusion in its simplest form:
cargo plans can break even when headline “on-time arrival” metrics look healthy.
Drift measures how far an ERD or CY Cutoff moves between its original and final values, expressed in calendar days.
Plain-English meaning:
Most ERD changes are small - but a meaningful long tail exists. Those larger shifts are infrequent, but when they occur, they overwhelm fixed planning assumptions.
Static buffers are built for the middle of the curve. Operational pain lives in the tail.
Across the system, CY Cutoff drift consistently exceeds ERD drift.
Average drift
Threshold comparison
Plain-English meaning:
Exporters often feel “safe” early because ERDs look stable - then get exposed later when CY Cutoffs move underneath them.
CY cutoffs move more often and by larger amounts than ERDs. That’s critical because CY is the last gate. Even small CY shifts can invalidate otherwise “safe” plans made earlier in the week.
If exporters feel blindsided late, this is why.
A late-stage change is defined as a change to ERD or CY Cutoff that occurs within the final 72 hours before the receiving window opens.
Plain-English meaning:
More than 1 in 4 CY Cutoffs changed inside the final three days - when trucks, labor, and documentation are already locked.
So far, we’ve looked at how windows move. Next, we look at where.
Some ports are simply harder to plan against than others. That’s what the Port Volatility Index (PVI) captures.
PVI combines:
into a normalized score (0-10) that reflects how quickly static planning assumptions break at a port.
A higher PVI doesn’t mean a port is “bad.” It means static assumptions break faster there.
Both ERD and CY move by more than two days on average - the highest combined drift observed.
What this feels like:
Even early plans can get invalidated. When things move here, they move far.
ERDs look manageable, but CY cutoffs slide by more than three days on average.
What this feels like:
Plans look fine until the last gate shifts underneath you.
Changes are common, even if they aren’t extreme.
What this feels like:
Constant re-validation. Planning fatigue builds over time.
ERDs stay relatively stable. CY cutoffs don’t.
What this feels like:
Early signals look reassuring - final execution is not.
Average drift is mid-range, but late-stage changes are meaningful.
What this feels like:
Things break close to execution, when flexibility is lowest.
Both ERD and CY move by about 1.5-2 days.
What this feels like:
Movement is expected. Adaptability matters more than precision.
Plain-English meaning:
These events are not typical - they are stress tests that show how quickly drift can stack when multiple changes coincide.
Static buffers fail in these scenarios by design.
Plain-English meaning:
The core reliability constraint for exporters is predictability, not punctuality.
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.
A vessel can be “on time” and still break export execution if the receiving window shifts underneath it.
This System Baseline establishes where volatility lives, how it behaves, and why exporters feel friction even in good reliability periods.
Each carrier deep dive that follows applies this same framework - definitions, thresholds, and charts - to show how individual carriers behave inside these terminal environments.
All definitions, thresholds, formulas, and exclusions used in this analysis are documented here:
Reliability Series - Methodology Appendix
https://www.tradelanes.co/blog/reliability-series-methodology-appendix
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