Service instability has emerged as a critical but often overlooked driver of perceived poor reliability in liner shipping, with recent analysis showing weekly disruptions have more than tripled on major trades since the pre-pandemic period.
In Issue 735 of the Sea-Intelligence Sunday Spotlight, the focus was on a key factor contributing to shippers’ perception of poor service levels: service instability.
Liner shipping is not merely the movement of cargo, but the consistent delivery of fixed, weekly scheduled services.
While vessel schedule reliability measures on-time arrivals, it fails to account for disruptions that are planned in advance and therefore excluded from these metrics.
To address this, Sea-Intelligence developed a new indicator to quantify service instability—defined as the percentage of liner services on a trade that experienced a non-standard cancelled or added sailing.
The findings point to a structural shift: the frequency of such disruptions in 2024–2025 has increased by a factor of 2.5 to 3.5 compared to the pre-pandemic baseline.
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On the Asia–North America West Coast trade, for example, service instability averaged 56 per cent in 2024–2025, compared to just 23 per cent during 2012–2019.
While pandemic-era volatility saw instability exceed 100 per cent, the current level represents a “new normal” more than double pre-pandemic levels.
Similar trends are observed across other major trades. Instability has risen by a factor of 2.9 on the Asia–North America East Coast route, 3.3 on Asia–North Europe, and 3.4 on Asia–Mediterranean.
This marks a fundamental operational change. Shippers are now contending with significantly more frequent disruptions, as weekly sailings are either cancelled or delayed into the following week—effectively eliminating service during the planned window.
