Assignment of orders in horizontal transport at sea-port container terminals

Quay cranes (QCs) represent the primary operational bottleneck at seaport container terminals due to their high capital intensity and role as critical nodes in global supply chains. Their productivity is strictly dependent on the efficient coordination of horizontal transport, specifically the assignment of transport orders to terminal trucks (TTs). While many terminals still rely on fixed TT-to-QC assignments, this approach often lacks the flexibility to handle disruptions and fluctuating workloads. This paper investigates the potential of a flexible, multi-criteria assignment procedure – considering work-in-process, travel distances, and QC waiting times – compared to traditional fixed assignments. The performance is evaluated using Logistic Operating Curves (LOCs), which map QC productivity against the number of deployed TTs. The results demonstrate that flexible assignment significantly outperforms fixed assignment in underload scenarios (low TT availability or high travel speeds), showing productivity gains of up to 17.85% during vehicle disruptions. However, this advantage diminishes as transport capacity increases. In high-utilization overload zones, the flexible method falls slightly below fixed assignment performance. This discrepancy is attributed to the timing of order assignment; making decisions when a previous task is completed, rather than at the last possible second, limits the system’s ability to react to real-time fluctuations. The study concludes that flexible assignment increases robustness during transport shortages, but achieving theoretical productivity benchmarks requires shifting toward late-assignment strategies.

Content

Subjects

Container Terminal

Productivity

Flexible Assignment

Logistic Operating Curves

DDC Class

388: Transportation

Funding References

Funding(s)

Betriebskennlinien für Containerbrücken

Files

Lizenz

https://www.springer.com/gp/open-access/publication-policies/aam-terms-of-use