Modeling the internal transport system in a containerport

Containerport operations consist of five components: navigation system, loading/unloading, container transfer, storage, and land interface. Usually, an analysis of port operations is performed through discrete simulation. An alternative modeling approach that jointly addresses three of the five components is presented. Internal transport is composed of three consecutive stages: unloading a container, transferring it to a yard, and finally placing it within a yard; this cycle operates in the reverse direction also. The main objective is to present an analytical tool to analyze the effect of different internal transport strategies on the efficiency of a containerport. The analytic model is based on queuing theory and relies on operational parameters such as fleet size, fleet configuration, capacity and configuration of cranes, speed of empty and full terminal tractors, and variations in travel distance between the wharf and storage yard. The analytic model allows the computation of terminal efficiency as a function of the effective capacity of container transference when any of the operational parameters change. The operational parameters mentioned above were obtained from an actual scenario at the port of San Antonio, Chile. A discrete simulation model was implemented to act as a validation benchmark. Results showed that the analytic model was a fairly accurate representation of the studied phenomenon, as well as an easy-to-use tool in assisting port operators with decision-making tasks.