| Summary: | 碩士 === 國立交通大學 === 運輸與物流管理學系 === 102 === This study focuses on the pick-up process of an international courier company, in which a courier starts a tour from the depot and ends by picking up the demand of the last customer point in a designated route. For the service-area districting aspect, we take into account the loading balance between each depot and a restriction of an upper bound on the service loading of a depot. Also, we divide the service area of a depot into many sub-service areas, and a courier pairing with a single vehicle conducts the pick-up service in each sub-service area. For the vehicle routing aspect, we assume that a demand point belongs to only one sub-service area, the customers’ demand is stochastic, an upper bound applies to the vehicle loading capacity, and the courier may go to the next demand point in the route without visiting a demand point with zero demand for a particular day. This study assists an international courier company in its long-term planning of the optimal service-area districting of each deport and the optimal vehicle route corresponding to each sub-service area. A courier uses an optimal route, which is fixed for a long period of six months to a year, for the pick-up service in each sub-service area to minimize the expected average total costs incurred in the responsible sub-service area. For our decision-making scenario above, we formulate the corresponding mathematical models, and propose an integrated solution approach that employs (1) a tabu search algorithm for solving the optimal districting problem and (2) a hybrid Genetic Algorithm (GA) utilizing an Optimal Computing Budget Allocation (OCBA) procedure, that effectively allocates the computing loading as evaluating solutions using Monte Carlo Simulation. Taking the benchmark instances in the literature, we tested the effectiveness of the proposed integrated solution approach. Our numerical results show that our approach is able to achieve an improvement for more than 10% from its initial solution, and the improvement is notable, especially for those small-size R-type problems (in which the demand points are evenly distributed geographically in the planning region). We conclude that the proposed integrated solution approach serves as a good one for the optimal service-area districting and vehicle routing for the pick-up service of an international courier company.
|
|---|
