Dynamic management model for offhire movements of a carrier fleet

This paper presents an innovative dynamic route management model for direct on-demand transportation services. In these scenarios, a carrier is hired for a transportation service from an origin to a destination point and then released. Subsequently, being in the off-hire condition, the carrier can wait in the destination point or move towards another loading dock. The aim of the approach is to identify the best route and the optimal waiting strategy of the carrier while in the off-hire condition, minimizing the dead-head movement costs and maximizing the expected profit originating from the forecasted demand. This model has been tested in the industry of the oil tankers fleet. So far this problem has been partially fronted with models which are focused on the evaluation of each loading dock profitability, lacking however to consider the opportunity of a continuous-moves routing in the off-hire condition. This analysis defines instead a dynamic strategy which estimates the future demand and is continuously updated by the other carriers movements and by the variation in the scenario. A set of Deviation Points and Waiting Areas are identified respectively as alternatives for the carrier off-hire movements and as areas in which the carrier has the possibility to stop and wait for a new order. These points are determined on a geographical map on behalf of statistical and economical considerations. Time constraints are also considered, especially in terms of Time Windows in which the carrier has to react to the demand and to reach the origin of the order.