A system dynamics analysis of the trans-Pacific trade lane during the pandemic

A consequence of the pandemic was significant disruption to global container flows from 2020 to 2022, with cargo time spent in containers, container ship congestion in ports, and container dwell times in terminals all peaking during this period. After reviewing 2020 and 2021 data for the trans-Pacific trade lane, this paper presents a system dynamics model that explains how these factors are related to each other. The model highlights the importance of the speed with which containers are loaded and unloaded for the dwell time of container ships in ports, the dwell time of containers in terminals, and rollovers (containers left behind). It is shown that port congestion propagates to all ports in the same port rotation (tour). An analysis of the mathematical model behind the system dynamics model indicates precisely when the "tipping point" is reached and congestion propagates. The mathematical model also suggests some remedies, like reducing the number of ports in port rotations and increasing productivity at one port to compensate for a loss of productivity at another port on the same rotation.