Optimum Port Investment: Sensitivity Analysis by Simulation

Abstract

The simulation model presented in this article is designed to plan port investment in terms of finding the optimum combination of number of berths, number of cranes, forklifts, and warehouse capacity. The model is adjusted according to the data availability and characteristics of port of Istanbul. Since most unloading operations are performed by shore based equipment, the port can handle more ships if the unloading rate could be increased with an additional supply of cranes. In such a case, the port would be operating at a higher efficiency without an expensive investment. Yet, there is a limit to increasing capacity through such gains in efficiency. Increasing the unloading rate would be of little use if forklifts are not clearing the apron and transferring the cargo into the transit sheds at a comparable rate; and no increase in the number of forklifts would help if there is no space in the warehouse. Given an arrival rate, available space in a warehouse is a function of: a) capacity of the warehouse net of movement isles, b) the number of days the cargo stays in the warehouse. In other words four basic bottlenecks may limit the capacity of a port. These are: a) warehouse capacity, b) number of forklifts, c) number of cranes, d) number of berths. The objective of this paper is to develop a model to identify the bottle neck area in an existing port and to enable increases in port capacity through improvements in unloading and wharfside operations as much as possible before the construction of another berth is recommended.