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 CY Cutoff - is where export execution actually happens.
This edition applies the same framework to CMA CGM (CMDU) to understand how receiving windows behave in practice once you stop measuring reliability as an arrival event and start measuring it as a receiving-window behavior.
All terms used here - 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 analysis is based on an observational system sample of executable export port-calls and is not a statistically randomized sample.
Filters applied:
A receiving window is considered moved if either ERD or CY Cutoff shifts by one calendar day or more from its originally published value.
Plain English meaning:
CMA CGM receiving windows are stable in a majority of port-calls - but nearly 46% still move. That level of movement is enough to create routine execution breaks even if vessel arrival performance looks healthy in traditional reporting.
Drift measures how far an ERD or CY Cutoff moves between original and final values, expressed in calendar days.
ERD drift distribution:
Plain English meaning:
Most CMA CGM ERD movement is small. But the tail is real - about 1 in 7 port-calls show 3+ days of ERD drift.
Static buffers are built for the middle of the curve. Operational pain lives in the tail.
Across the CMA CGM sample, CY Cutoff drift exceeds ERD drift.
Average drift:
Threshold comparison:
Plain English meaning:
The same system pattern holds, but the gap is especially clear here - CY Cutoffs drift materially more often than ERDs. Exporters can feel “safe” early because ERDs look manageable, then get exposed when CY Cutoffs move underneath the plan.
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:
Late-stage change is common in this CMA CGM sample - roughly 3 in 10 ERDs and nearly 3 in 10 CY Cutoffs change inside the final 72 hours. That is the dispatch lock problem: plans feel stable until the moment options are limited.
So far, we’ve looked at how windows move. Next, we look at where.
The Port Volatility Index (PVI) combines:
into a normalized score (0-10) representing 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.
Below is a Plain English interpretation of CMA CGM’s highest-volatility ports in this sample. Ports with very small sample sizes should be interpreted cautiously.
What this feels like:
This is a high-severity, late-stage environment in a limited sample. When it moves, it can move far - and CY changes often land late.
What this feels like:
Frequent re-validation. ERD drift is meaningful, and late-stage CY movement is common enough to create last-minute rework.
What this feels like:
A port where CY volatility dominates. Plans can look workable early, but CY Cutoffs still shift often enough to force adjustments.
What this feels like:
Low average ERD drift but meaningful late-stage behavior. The plan can feel stable until close-in updates appear.
What this feels like:
A more forgiving environment in this sample. It does not eliminate risk, but it reduces how often a plan must be rebuilt.
Plain English meaning:
These events are not typical - they are stress tests that show how quickly drift can stack when multiple changes coincide.
Top examples in this sample:
Static buffers fail in these scenarios by design.
Plain English meaning:
CMA CGM’s receiving-window stability is the majority state - but the movement rate remains high enough that predictability has to be managed explicitly. Arrival-based reliability metrics will not explain the day-to-day execution breaks exporters feel.
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 CMA CGM edition shows:
Methodology and definitions:
Reliability Series - Methodology Appendix
https://www.tradelanes.co/blog/reliability-series-methodology-appendix
Evergreen - publishing soon.