Synchromodal Logistics Optimization

Why is Multimodal Scheduling Hard?

Multimodal planning can involve a number of different transport modes within a single journey of a container. Which each leg and each new mode more complexity is added.

Imagine a shipment that is to be transported from Factory A to Customer B, both of which are a long distance from a port. This will require five legs, shown in the table below:

Leg 1 Factory A to Intermediate Terminal IT1 via Truck
Leg 2 Intermediate Terminal IT1 to Port of Loading P1 via Rail/Barge/Feeder
Leg 3 Port of Loading P1 to Port of Discharge P2 via Ship
Leg 4 Port of Discharge P2 to Intermediate Terminal IT2 via Rail/Barge/Feeder
Leg 5 Intermediate Terminal IT2 to Customer B via Truck


The majority of the journey will be made by ship as this is the most economic. Hinterland movements can be made via rail, barge or feeder vessel and connect the port to intermediate terminals. Getting to and from the intermediate terminals requires truck movement.

Multimodal Scheduling

Schematic of Multimodal Routes from A to B via Intermediate Terminals (IT) and Ports (P). In reality many more terminals and ports could be considered.

For such a movement there are many choices:

  • Leg 1 - ~10 reasonable choices for the inland terminal
  • Leg 2 - ~5 reasonable choices of deep sea port for loading the container
  • Leg 3 - ~5 possible ports for discharging the container
  • Leg 4 - ~10 possible inland terminals close to the final destination

This gives 2500 possible route combinations to move from Factory A to Customer B.

However, for each leg there are multiple options for carriers and services. Assuming there are 10 options for each leg there would be a total of 250,000,000 possible options to choose from for a single shipment.

The problem can be made more complex when taking into account multi-leg ship movements and combinations of hinterland modes.

When all the possible options for the shipment have been found there is still the issue of how to determine the “best” choice. Should cost be the sole factor or does the emissions produced also have an impact? Is there a strict deadline for the shipment? Often a combination of factors such as cost, risk, emissions and arrival time come in to play when finding the best fit route for a shipment.



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