A Study of Determining Fleet Size and Vehicle Routing for Two Different Geographic Regional Areas

• Main Authors: Kuo-Yao Chen, 陳國耀
• Other Authors: Juh-Wen Hwang
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/05596016313174506011

碩士 === 國立東華大學 === 運籌管理研究所 === 101 === Nowadays, the chain convenience stores (CVS) in the commodity replenishment are unified by distribution center. In order to satisfy CVS small quantities demand patterns, and avoid the high inventory level increasing the costs. Thus, the fleet of the distribution center has the characteristics of high frequency, and distributes small quantity. The main objective of our study is to determine the fleet size and the vehicle routing problem in two different geographic regions areas, and selects CVS as the target. We divide the problem into two phases: The first phase is to plan the fleet size of each zone. By using the results in the first phase, the second phase is to solve the vehicle routing problem in each zone. In fleet size aspect, first classify the district in the regional areas and following the main artery to connect all districts. Second, based on the 3+2 zip code to partition the district, the total demand can’t exceed the effective vehicle capacity in each sector. Third, setting several seed points in each district, the seed point treat as one or more vehicle. The rule of setting our seed point is according to main artery. Fourth, introducing the model includes the heterogeneous fleet, multi-trips to solve. Finally, calculate the solution of the fleet size and each vehicle service scale at distribution center in different geographic regional areas. In vehicle routing problem aspect, planning each vehicle route in each territory by using exactly distance from the prior solution. The approach based on varies geographic environments will using different method to solve. If the population is evenly distributed in a one area within the developed transport network of the regional area, we will use traveling salesman problem (TSP) to solve. However, if the population distribution is more dispersed in area and the transportation network is not convenient, the method for solving by traveling salesman path problem (TSPP). Because the loads constraint by goods size and the vehicle volume lead the vehicle capacity become inefficiency. We adjust the each vehicle capacity to compare the solutions. As the result, while decreasing the vehicle capacity, the fleet size and vehicle load will increase. However, the service level of delivery is efficiency by reduce the vehicle capacity.