Research On Airline Micro Fleet Planning Approach

The fleet is the carrier of an airline's transportation and production.The fleet planning is one of an airline's important strategic planning contexts,which is crucial to the future development of an airline and is also fundamental to the decision-making process of an airline's management including flight scheduling,aircraft routing and assignment,and revenue management.The benefit of airline's transportation and production is largely dependent on the effectiveness of the fleet planning.Therefore,it is greatly significant to make a study of the size and structure of an airline's fleets so as to be able to optimize its transportation products and enhance its transportation efficiency with the fulfillment of the requirements for an airline's simulated operation elements such as network characteristics,flight schedule,demand and fare level,etc.For marco-fleet planning approach,few characteristics of technical and economic performance on aircraft type's assignment to flight are reflected.In order to solve this shortcoming,this paper,focusing on the linear route network with a single operation base,constructs a mathematical model for fleet planning based on the flight circle time sequence network using fleet assignment technology.It also employs the simulated annealing algorithm to design a random path decomposition algorithm.The results of numeric example show that the proposed algorithm is with high precision and the solving speed.Then,the flight circle time sequence network is extended to the flight string time space network for the linear route network with a multi-base operation.The corresponding mathematical model for such a network operation mode is presented and a two-stage algorithm is also designed based on the scenario aggregation.The results of numeric example show that the presented algorithm outperforms the use of the deterministic approach in terms of fleet operation achievements.Finally,this paper incorporates a passenger network revenue optimization model into the above stochastic fleet planning model for hub-and-spoke network operation mode.The two-stage algorithm is again used to solve such a problem and the results indicate that the model with enhanced revenue modeling is more applicable to the hub-and-spoke route network structure.For the above fleet assignment-based micro fleet planning approach,an airline's future flight schedule can be hardly simulated accurately.This paper studies the route capacity-based micro fleet planning approach.Based on the maximum flight frequency on each route,the flight hours available to aircraft fleets,and the supply-demand balance on each route,this paper constructs an uncertainty fleet planning model with stochastic demand with the objective of maximizing airline fleet operational profit.Through the linearization of the expected revenue nonlinear function,the probabilistic revenue optimization model is isolated from the fleet planning model.After that,a decomposition algorithm is tailed to solve the model.Through the testing with an airline's real operation data and comparison to the generic algorithm,the results show that the advantage of the presented approach.Furthermore,the passenger revenue network optimization model is combined with the presented model and the decomposition algorithm is also employed to solve the model.The numeric example is used to verify the benefits of such a kind of fleet planning model in hub-and-network environment.As a matter of fact,the existing route capacity-based fleet planning approaches could not accurately reflect the dynamic fluctuations of passenger demands and the non-monopoly of an airline's micro fleet planning environment.In order to solve these problems,this paper constructs a fleet planning approach based on the optimized allocation between routes and aircraft types with discrete time.The Lagrange relaxation algorithm is used to design the solution algorithm for the presented model.The results of numeric example show that the aircraft fleet resulting from the proposed approach is more stable than the use of the fleet assignment-based approach.In addition,the difference of the required seating capacity with time dynamic fluctuation can be well reflected from the model presented in this paper as apposed to the use of the route capacity-based approach.On the other hand,this paper combines the impacts of the route capacity allocation scheme of other competitors on an airline itself with the route capacity-based fleet planning approach.It also constructs a multi-airline mathematical model for fleet planning and the concept of equilibrium optimum is employed to design a heuristic algorithm to solve the model.The results of numeric example indicate that the presented algorithm can obtain the equilibrium solution to the model.Through using Monte Carlo simulation approach to compare with the classic fleet planning model,this paper verifies the advantages of the proposed approach.