A comparative performance analysis of airline strategic alliances using data envelopment analysis

As “open skies” agreements became more common among different countries and thus began to open up international routes to further competition, the global airline industry has undergone accelerated structural changes for the last two decades. These changes include the consolidation and expansion of airline strategic alliances throughout different regions of the world. Though airline strategic alliances are generally perceived to be a major driver for enhancing the operating efficiency and the subsequent competitiveness of participating member airlines, the concrete evidence supporting such a perception is still lacking in the literature. This paper is one of few attempts to evaluate the comparative efficiency of the strategic alliances among global airlines and then assess the managerial impact of airline alliances on the airline's comparative performances.     

Robust planning and disruption management in roll-on roll-off liner shipping

This paper presents different strategies for handling disruptions in fleet deployment in roll-on roll-off liner shipping, which basically consists of assigning a fleet of vessels to predefined voyages at minimum cost. A new mathematical model of the problem is presented, including a set of robust planning strategies, such as adding slack and rewarding early arrivals. To solve real-life instances a rolling horizon heuristic is proposed. A computational study, where we also propose some recovery planning strategies, is conducted, and simulation results show that adding robustness significantly reduces the actual cost of the plan and the total delays of the voyages.     

Airfreight forwarder’s shipment planning under uncertainty: A two-stage stochastic programming approach

This paper addresses the shipment planning problem with random processing times in intermodal logistics via transfer ports. Shipment activities are divided into two groups according to regional settings. Activity processing times in region A are assumed to be random while those in region B are deterministic. At the beginning (stage 1), the forwarder assigns agents to all job activities (planning decision). In case a shipment delay is observed, an in-process adjustment (recourse decision) is implemented (stage 2). A two-stage stochastic programming model is established and an illustrative example is discussed. Managerial insights are presented in a simulation study.     

A dynamic approach for aircraft assignment and maintenance scheduling by airlines

The problems of assigning planes to flights and of fleet maintenance operations scheduling are considered in this paper. While recent approaches make use of artificial intelligence techniques running on main frame computers to solve combinatorial optimization problems for nominal operations, a dynamic approach is proposed here to face on-line operation conditions. The proposed solution mixes a Dynamic Programming approach (to cope with the fleet assignment problem) and a heuristic technique (to solve the embedded maintenance schedule problem). When applied to a medium charter airline, this approach shows acceptability characteristics for operational staffs, while providing efficient solutions. The proposed solution scheme can be considered as the basis for the development of an on-line decision support system for fleet operations management within airlines.     

高速铁路兰州至张掖三四线运输需求分析

高速铁路兰州至张掖三四线运输需求是确定其建设方案、投融资模式、主要技术标准、运输组织和运营管理方案的决策依据,更是确定铁路经济效益和修建可行性的关键指标。通过对旅客运输径路比较分析,结合区域路网构成确定高速铁路兰州至张掖三四线可能的功能定位,包括"城际功能为主"、"城际、通道功能并重"和"通道功能为主"3种情景。再基于"情景分析"的基本原理,利用"四阶段法"预测高速铁路兰州至张掖三四线处于3种不同情景下的运输需求,即远期客流密度分别为805万人/a、1426万人/a和1852万人/a。     

The Nicaragua Canal: scenarios of its future roles

Connections between the Atlantic and Pacific oceans are vital for international trade. Since 1914, the Panama Canal has provided ships with a direct interoceanic canal for crossing the Atlantic and Pacific oceans. The geographical advantage of the Panama Canal allows it to enjoy an exclusive position in international seaborne trade. Passage demand through the canal has increased continuously since its opening, with about 12,000 vessels travelling through it in 2013. However, the Panama Canal’s monopoly in interoceanic canal operations may soon come to an end. In 2012, a memorandum of understanding was signed between the Nicaraguan Government and a Chinese investor to construct the Nicaragua Canal, which will be built about 400 nautical miles from the Panama Canal. It is expected that the Nicaragua Canal will be operational by 2020. The proposed canal will not only provide an alternative route for vessels to pass between the Atlantic and Pacific oceans, but will also trigger dynamic changes in seaborne trade patterns. To assess the long-term benefits of the proposed canal, we use a scenario planning method in this study to provide a framework for constructing several scenarios for 2030, 10 years after the anticipated construction of the canal. To develop the scenarios, we consider three macroscale drivers, namely politics, economics, and environment, and the causal relationships between them. Combinations of pairs of drivers are used to generate dominant scenarios to anticipate the role of the Nicaragua Canal with respect to future international trade. The analysis presented in this study will provide transport geographers and other major stakeholders with alternative mindsets into the future spatial changes in and development of maritime transport.     

对内蒙古中西部铁路中期发展战略规划的探究

以呼和浩特铁路局为例,结合运输辐射区经济社会环境、行业机构和自身条件,分析内蒙古中西部铁路发展的优劣势和面临的机会与威胁,探讨全铁路局“十一五”后三年“三步走”中期战略规划,以提升企业经营发展内涵质量。     

Slot auction in an airport network with demand uncertainty

This paper investigates the effectiveness of airport slot auction by developing a two-stage model, which distributes slots among competing airlines using an ascending-bid multi-unit auction. Airlines assign different values to slots at peak and off-peak periods, and each carrier has its private (subjective) forecast of future demand. Conditional on the slots available to them, airlines compete in frequency, fare, and aircraft size over a congested airport network. The market outcome under such a scheme is benchmarked to those under an ex ante allocation and an ex post allocation by a social planner. Comparison results suggest that the auction-based scheme is inferior to the other two schemes when there is little fluctuation in demand, whereas the auction-based system is more effective when there is substantial demand uncertainty. Auctioning some grandfathered slots can improve social welfare but the marginal effect may diminish quickly.     

The multi-period service territory design problem – An introduction,a model and a heuristic approach

In service territory design applications, a field service workforce is responsible for providing recurring services at their customers’ sites. We introduce the associated planning problem, which consists of two subproblems: In the partitioning subproblem, customers must be grouped into service territories. In the scheduling subproblem, customer visits must be scheduled throughout the multi-period planning horizon. The emphasis of this paper is put on the scheduling subproblem. We propose a mixed integer programming model for this subproblem and present a location-allocation heuristic. The results of extensive experiments on real-world instances show that the proposed heuristic produces high-quality solutions.