Analysis And Optimization Of Air Logistics System

With the increasing of air cargo volume, the requirements of cargo owners are higher and higher. Only emphasizing the cargo transport capacity can't meet the economic development. If lacking effective ground operation, the advantages of air transport are unable to bring into play. Therefore, the organic combination of air cargo transportation and logistics service, is the inevitable result of modern logistics development. Air logistics is organically combined the logistics function form the origination to destination based on the air transportation, to meet the demands of shippers and relize the efficiency and benefit of the logistics service.The article discussed the concept, composition of the air logistics system. According to the cargo handling flow, the problems of import and export handling in the air logistics center, cargo loading, transportation route and distribution were researched to increase the operation efficiency and benefit of air logistics system.Firstly, the article analyzed the concept of air logistics, air cargo and air logistics system. Three dimensional concept of air logistics system was given, which pointed out that the air logistics system was composed of network, logistics activity and management. The system optimization aspects were put forward.Secondly, the article disscued the operations of air logistics center, cargo loading, transportation route and distrubition based on the the air logistics service process. The operation of air cargo export handling system influenced the speed of air cargo transportation. The article established the stochastic Petri net and the homogeneous Markov chain based on the work flow of air cargo export handling system. the article calculated steady probability of the Markov chain and studied the operation efficiency and time capability of the SPN. Then some advises were given to improve the efficiency of the air cargo export handling system. Air cargo Unit Loading Device (ULD)loading problem was to decide the type, quantity of ULD and the loading mode, so as to meet transportation requirements. The article discussed the advantages and disadvantages of two loading modes, which were Loading items of Agent and Loading items of Destination. The mixed integer linear programming model was constructed, which target function was minimum sum cost including loading cost at origin airport, loading cost at transfer airport, air freight and ULD using cost. The model was solved by using the heuristic algorithm based on effective space.The cargo is transported in the belly of passenger aircraft or the cargo aircraft, the article analyzed the cargo routing problems in the different way. According to the cargo loading in the belly of passenger aircraft, an integrated model was built combining fleet assignment and air cargo transportation problems. The model was formulated as a mixed integer program which object was to maximize the operating profit and a Benders Decomposition approach was given to solve the problem. Under the condition of cargo aircraft transportation, a model was also put forword to integrated optimization of the cargo routing and fleet routing problems. The model was sloved by a heuristic algorithm according to the transportation distance and the transport times. Lastly, the article discussed the single target delivery time points decision problem based on the p-median model. Three models were built to solve the problem. The targets of the models were minimum delivery time, least delivery times and minimum transportation cost under the condition of freight discount. And taking the air cargo transportation as a case study, the delivery points were calculated based on the models.The research of the thesis was foucs on the subject problems existing in the air logistics enterprise operation. In terms of overall optimization, considering all sectors, mainly to the principle of efficiency and economy, the goal of system optimization was realized through the mathematics models. In the period of air logistics development, air logistics enterprises must turn from extensive management into lean management. System operation efficiency increasing or reducing costs would play an important role to improve service quality, improve the satisfaction and obtain more benefits for the enterprises. From the analysis of air logistics system concept, air cargo import and export handling, air cargo loading, routing and distribution, the article should offer the references to the air logistics enterprises to increase the operation efficiency and effectiveness.