| Summary: | 碩士 === 國立中央大學 === 土木工程研究所 === 95 === Due to scarcity of land resources, urban streets in Taiwan, especially those at local street level, are often not wide enough for big cars performing temporary parking and home delivery services. To solve this problem, few home delivery companies have invented a new type of vehicle routing and operations which involves two types of vehicles. During the operation, a big vehicle departs from the depot and travels along several “legitimate” stops whereas a set of small vehicles performs delivery to customers and, if necessary, reloads the commodity either from the depot or from the big vehicle at stops and then continues their work. The objective of the operation is to minimize the total travel cost. This new service not only overcomes the difficulty of accessing “narrowed” local streets with high-capacity big cars but also saves the low-capacity small vehicles a number of times to and from the depot to reload the commodities.
This problem can be regarded as an extension of the Vehicle Routing Problem and for easy of reference is named as the Feeder Vehicle Routing Problem (FVRP). In this research, the FVRP problem is formally formulated as a mixed integer programming problem and two heuristics, namely the method of average and the threshold method, are proposed for solving it. 17 test problems modified from a set of classical VRP benchmark instances were extensively examined. The results show that the method of average outperforms the threshold method in terms of the objective value, though the latter does have some nice features from the algorithmic point of view. In addition, we also observed that more candidates of stops allowed for the big car, the better objective value would be obtained. To conclude the research, a few remarks were made in the end.
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