Abstract
The container traffic varies to and from every port in the world, so that container imbalances must be economically adjusted to coincide with actual demand. With operational data at the container yard at the port of Kobe, the procedure was shown to find a formula evaluating how many containers are needed for each container space aboard ship-so many ashore being loaded and so many ashore being unloaded for every container at sea. The uncertainty in operation associated with container demand was also evaluated to fix the optimum number of containers, using a simple random walk model with two reflecting barriers. These may help when minimizing the operating cost by making available the right containers at the right place, at the right time.
