In issue 735 of the Sea-Intelligence Sunday Spotlight, we analysed a key factor behind shippers’ perception of poor service levels: Service instability. Fundamentally, liner shipping is not just the ability to move cargo from one place to another, but the provision of a fixed scheduled weekly service to do so. While vessel schedule reliability measures on-time arrivals, shippers still often face disruptions that may have been scheduled well in advance, and such disruptions will – by definition - not be captured in a measure of vessel schedule reliability. To quantify some such disruptions, we developed a new metric that tracks service instability, calculating the percentage of liner services on a trade that have seen a non-standard missing or added sailing. Our analysis reveals a fundamental shift, with the frequency of these weekly disruptions in 2024-2025 increasing by a factor of 2.5-3.5 compared to the pre-pandemic period.
The Asia-North America West Coast trade, shown in Figure 1, clearly illustrates this structural shift. After the extreme volatility of the pandemic, which saw instability peak above 100%, the post-pandemic period of 2024-2025 has settled into a “new normal” of service instability averaging 56%. This is in stark contrast to the pre-pandemic (2012-2019) period, where the average was just 23%. This means that the instability in the service provision has increased by a factor of 2.5 on this trade. (....)