當日快遞路運網路設計之研究

The Ground Network Design Problem of the Same Day Express Service

社會需求日殷的當日快遞服務，吸引數家翌日送達路線貨運業者加入。路線貨運業者如何充分利用現有的路面運輸站所，並配合快遞服務的營運特性，設計出成本最佳化的路面快遞運送網路與車輛配送路線是業者加入快遞市場重要研究課題。本研究是透過數學模式之構建與演算法之開發，在符合快遞服務時限之要求內，以不分割現行路線貨運業路運管理分區體制下，規劃全省快遞速運分區，同時在各速運分區內由已知之速運站選擇具中繼功能之總站並規畫總站聯繫速運站的車輛路線，使整體營運成本最低。本研究以國內三大之D路線貨運業者為實證對象。實證結果顯示，演算所規畫之當日快遞網路與營運計畫之成本確實能明顯優於業者現況。

Traditionally, time definite carriers only offer a 2-day regular groundservice to shippers in Taiwan. As the result of a gradual increase of demand forand a higher investment return on the express services, more and more timedefinite carriers enter the same day express services market. However, servicecharacteristics and time commitment for regular and express ground services arequite different. Therefore, carriers typically design a separate anddistinguished delivery network for each of the two services. For a set ofexpress service centers, the gruond express service network design problem is tosimultaneously design a hub-and -spoke network and determine vehicle routes sothat the total operating cost is minimized while meeting the operational andorganizational constraints. We construct a bi-level mathematical model and alsodevelop a heuristic algorithm based on the bi-level structure of the problem.We use one of the top three time definite carriers in Taiwan for performancetesting. We compare our solutions against the global optimum in a small scalenetwork, and also against the carrier's current operations in its large scalenetwork. Our computational results are encoruaging and show the potential ofapplying this approach to design carrier's logistical express system.