Vehicle Routing and Scheduling Problems with Time Constraints and Balanced Workload
| Autor: | Ting-Chi Chang, 張廷吉 |
|---|---|
| Rok vydání: | 2000 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 88 In this study, issues of vehicle routing and scheduling problems arising in local distribution centers are addressed. Due to the evolution of local economy from production-oriented markets to customer-oriented markets, a large number of distribution centers and the associated convenience stores are established in major metropolitan areas. Since the distribution services of commodities provided by distribution centers to convenience stores have tremendous impacts on the cost-effective performance of a firm and the level of customer services, issues of planning and management of commodity distribution have been received great concerns in practice. Theoretically, the planning of commodity distribution services is one type of vehicle routing and scheduling problems and can be improved through the application of optimization techniques. The vehicle routing and scheduling problem can be treated as a combinatorial optimization problem in nature and is NP-hard problem. First, we analyze the vehicle routing and scheduling problem arising in local distribution centers. The vehicle routing and scheduling problem under consideration is analyzed in terms of the following criteria: (1) to minimize the number of vehicles needed to provide the required distribution service, (2) to minimize the total travel distance needed to complete the total distribution service, (3) to ensure that every route is balanced in terms of workload, and (4) to ensure that the delivery time of every route is within the required duration. Next, an optimization model for describing this problem is explored and formulated. A heuristic-type solution method is developed by exploiting the property of the developed model. The developed heuristic consists of three stages. First, we generate an initial solution using savings method. Second we devise five procedures using one-point movement, two-point exchange, 2-opt improvement, reinitialization, and infeasibility improvement. Third, we ensure that every route is balanced in terms of workload. A real-world data is collected from a local distribution center and its associated convenience stores. The collected data is used for testing and implementation of the proposed approach. Results suggest that the proposed approach can achieve the foregoing objectives. The developed heuristic is fast and has improved upon previous best-known solution. It can obtain solution of higher accuracy and provide more scheduling information that has substantial contribution to operate the planning and management of commodity distribution. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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