A comparison of optimization models to evaluate the impact of fuel costs when designing new cruise itineraries

The itinerary design is a problem that belongs to the class of cruise supply. The development of cruises’ itineraries to offer on the market is a long process. Given a ship located in a specific world’s basin, given a duration and a homeport, an itinerary has to be planned choosing a sequence of ports to visit among a set of available ones. The itinerary must be characterized by a schedule, which comprehends the arrival time and the departure time of the ship for each port. The objectives to pursue in the decisions are the maximization of both the customer satisfaction and the revenue and the minimization of the costs. In this paper the focus is on costs, that depend on fuel consumption and ports’ services. The fuel cost is function of the speed of the ship. Starting from a model recently proposed in the literature for solving the cruise itinerary designing problem (CIDP) (Ambrosino et al. in Proceedings of 15th IFAC Symposium on Control in Transportation Systems, Savona, Italy, June 2018, [3]) in which fuel costs were based on classes of speed, a different model has been developed for including a more precise fuel cost computation. The fuel costs represent a great part of the company costs, influencing the operative margin. Thus, the fuel consumption is here computed in terms of metric tons for each single speed. The model has been tested solving real cases of Costa Crociere in the Mediterraneo basin. The obtained solutions have been compared, both in terms of cruise route and objectives values with those obtained by the previous model used by the company to define optimal itineraries.