Fleet deployment optimization models.Part 2

The fleet deployment problem for the one origin,one destination fixed-price contract requiring the transport of a given total amount of cargo within a given period is formulated and solved for the case that one or more cost components are given staircase functions of time. A computer program has been developed to implement the solution of this problem. The fleet deployment problem with one or more costs being random variables with known probability density functions is also formulated. Analytical expressions for hte basic probabilistic quantities, i.e the probability density function,the mean and the variance of the total operating cost, are presented. Finally, sample results are presented and discussed and some extensions for further research are suggested.     

Fleet deployment optimization models. Part 1

The problem of minimum-cost operation of a fleet of ships that has to carry a specific amount of cargo between two ports in a given time period for a specific, fixed contract price is studied. Detailed and realistic operating cost functions are developed. Sensitivity analyses are performed to study the effects of small or large changes in one or more cost components on the total costs. A realistic model for the annual transport capacity as a function of speed is also used, in contrast with the linear relation most often used in the literature. The full load and ballast speeds for those ships of the fleet that we operate are selected to minimize the total fleet operating costs including lay-up costs for unused vessels, using nonlinear optimization algorithms.