| dc.description.abstract | Cargo Fleet routing and flight scheduling are essential to airline cargo operations. In particular, they always affect the usage efficiency of facilities, the establishment of timetables and the crew scheduling. As a result, they are essential to carriers’ profitability, level of service and competitive capability in the market. However, most of the airlines in Taiwan currently adopt a trial-and-error process for cargo fleet routing and flight scheduling practices. Such an approach is considered to be less efficient when the flight network become larger, and can possibly result in an inferior feasible solution. In the past most research on airline scheduling was mainly focused on passenger transportation, which is fundamentally different from air cargo transportation. In particular, airport selecting in service network design is typically in the stage of long-term plan in passenger transportation, but in cargo transportation, due to possibly significant demand changes in short-term operations, carriers may perform their airport selecting, fleet routing and timetable setting together in the stage of short-term plan, according to considerations of demand and profit. Moreover, passengers are more sensitive to time than cargos. Too many transfers in a transport service may result in significant loss of passengers, but not much loss of cargos. Besides, cargos with the same OD may be sensitive to different times, which can be incorporated into fleet routing systematically in order to find the most effective transport plan.
In this research, given the operating data, including fleet size, airport flight quota and available time slots, cargo handling cost at airports and flight cost, on the basis of the carrier’s perspective, we develop an integrated scheduling model by combining airport selecting, fleet routing and timetable setting, with the objective of maximizing the operating profit, subject to the related operating constraints. The model is a useful planning tool for cargo airlines to determine suitable service airports, fleet routes and timetables in their short-term operations. We employ network flow techniques to construct the model, which include multiple cargo- and fleet-flow networks in order to formulate the flows of cargos and fleet in the dimensions of time and space. In the cargo-flow networks, different from that in the past research, we construct multiple OD-time-pair time-space networks on the base of cargos’ timeliness. In the fleet-flow networks, we use an integer flow network to formulate the periodical fleet routes. Some side constraints set between the cargo- and fleet-flow networks according to the real operating requirements. The model formulated as a mixed integer program that is characterized as an NP-hard problem. We employ a mathematical programming solver and develop a heuristic to solve the problem. Finally, to evaluate the model and the solution algorithm, we perform a case study using real cargo operating data from a major Taiwan airline. | en_US |