| 摘要: | 車隊排程與班次表的建立對城際客運業者的營運成本、利潤、服務品質及市 場競爭力有相當大的影響。隨著經營規模的成長與營運效率的要求，近來有學者 基於城際客運業者立場，發展最佳化的排程規畫模式，以改善傳統的人工經驗排 班方式。然過去學者在此方面之研究，大多基於預測之平均需求值，進行車隊排 程與班次表建立，忽略了實務營運上，每日的旅客需求的隨機變動特性。此等隨 機性需求對規劃的最佳化排程與班次表可能產生相當的影響，若隨機性過大，對 真正的營運需求而言，甚至可能造成原規劃的最佳化排程與班次表，失去其最佳 性。因此，本研究從城際客運業者的立場，考量日常營運之隨機需求變動及實務 的營運限制，並以業者最大營運利潤為目標，構建一確定性及一隨機性需求之車 隊排程暨班次表規劃模式。本研究模式期能於未來實務的應用上，提供為有效的 工具，以期幫助長途客運業者規劃最佳的車隊排程與班次表。 本研究利用網路流動技巧構建確定性需求排程模式，此模式將含有多個人流 時空網路與車流時空網路，以定式旅客與車輛在時空中的流動情況。此確定性需 求排程模式可定式為一多重貨物網路流動問題，屬NP-hard 問題。本研究進一步 修正確定性需求模式中之固定需求值為隨機需求值，建立以模擬為基礎之隨機性 需求車隊排程模式，並利用路段及路徑兩觀點發展路段基礎與路徑基礎兩種策略 之啟發解法。本研究利用數學規劃軟體配合電腦程式求解兩種需求排程模式。為 比較確定性與隨機性需求模式及解法，在隨機營運環境中的績效優劣，本研究發 展一模擬評估方法。最後，為測試本研究模式、解法與評估方法的實務營運績效， 本研究以國內一城際客運公司的營運資料為例，並以C 語言程式結合數學規劃 軟體進行實例分析，進而提出研究結論與建議。 Vehicle fleet routing and timetable setting are essential to inter-city bus carriers’ operating cost, profit, level of service and competitive capability in the market. With the growing scales of carriers and the increasing requests of operation efficiency, an optimal scheduling model was recently developed to improve the traditionally manual way in fleeting routing and timetable setting. However, the model was established based on an average passenger demand as input to produce the final timetable and fleet routes, neglecting the stochastic characteristics of daily passenger demands in actual operations, which could affect the optimal fleet routes and timetables. If the demand is wildly changed in daily operations, then the original schedule could be disturbed to lose its optimality. In the past, the effect of the stochastic disturbance on the optimally planned schedule was rarely researched in either practices or academics. Considering the stochastic characteristics of daily passenger demands in actual operations, in this research, on the basis of the carrier’s perspective, we developed a deterministic-demand and a stochastic-demand scheduling models, with the objective of maximizing the carrier profit, subject to the real operating constraints. The models are expected to be useful planning tools for inter-city bus carriers to solve their optimal vehicle fleet routes and timetables in their short-term operations. We employed network flow techniques to construct the deterministic-demand scheduling model, which included multiple passenger-flow and fleet-flow time-space networks in order to formulate the flows of passengers and vehicle fleet in the dimensions of time and space. The deterministic-demand scheduling model was formulated as a multiple commodity network flow problem that is characterized as an NP-hard problem. We further established the stochastic-demand scheduling model by modifying the fixed demand parameters in the deterministic-demand scheduling model. Furthermore, we developed a simulation-based heuristic with link-based and path-based algorithms to solve the stochastic-demand scheduling model. We employed a mathematical programming solver, coupled with computer programs, to solve the deterministic-demand scheduling model. To compare the performance of the two models and the solution methods under stochastic demands in actual operations, we developed a simulation-based evaluation method. Finally, to evaluate the models, the solution methods and the evaluation method in practice, we performed a case study using real operating data from a major Taiwan inter-city bus carrier, with the assistance of C computer programs and a mathematical programming solver. Then show the conclusions and suggestions. |
