The effects of open skies agreements on transatlantic air service levels

This paper examines the effects of Open Skies agreements on service levels in transatlantic aviation markets. Our route analysis reveals that Open Skies agreements between European countries and the US have resulted in both increases and decreases in service levels. Of the 22 European countries with US Open Skies agreements in place by 2007, only seven demonstrated increases in service levels while six showed reductions. Five countries saw no significant change and the remaining four have yet to receive direct transatlantic service, suggesting that liberalization alone does not lead to service level increases.     

Investigating the effects of service recovery quality elements on passengers' behavioral intention

This study intends to analyze how the elements of restoring the quality of airline service influences the airline image, recovery satisfaction, and behavioral intentions of airline passengers. For this testing, a survey was conducted on passengers with an experience of dissatisfaction of airline services. A total of 240 responses were analyzed by using structural equation modeling. The results revealed that among the recovery quality elements, promptness had a positive influence the image of the airline. Additionally, a recovered image of the airline had a positive influence on the recovery satisfaction and behavioral intention. The findings of this study may improve our understanding of consumer responses to the airline company's efforts to recover service failure.     

Analytical models of rail transportation service in the grain supply chain: Deconstructing the operational and economic advantages of shuttle train service

This paper introduces conceptual and mathematical models of the domestic grain supply chain incorporating trucking, elevator storage, and rail transportation. We compare conventional rail service supported by country elevators with shuttle service supported by terminal elevators across three critical transportation service dimensions: travel time, cost, and capacity. Even after taking into account trucking and elevator storage, the time and cost model results indicate that shuttle service transports grain faster and reduces logistical supply chain costs, respectively, relative to conventional service. The rail capacity model results demonstrate that shifting grain from conventional to shuttle service significantly increases rail capacity.     

Improving the design of urban loading zone systems

Despite the ubiquity of loading zones in most commercially dense streets of medium and large cities, there exists no generally acknowledged procedure to establish their number, location and management system. We propose a methodology divided in two steps, where the first one estimates the required number of loading zones on a given street and the second one locates them taking into account the delivery characteristics of the retail establishments they will be serving. The application of the methodology is tested in four streets in the Spanish city of Seville, following a retailer survey to collect all the relevant data. The results provided by the application in terms of number and location of loading zones are simulated together with other scenarios with different numbers of loading zones, and the outcomes are compared with the existing situation. The new methodology results in an improvement in the level of service provided with a similar – or smaller – number of loading zones, but most importantly causes a significant reduction in the distances between loading zone parking spaces and final destinations.     

Collaboration decisions on disruption recovery service in urban public tram systems

This research focuses on the decisions on recovery services to deal with short-term disruptions in public tram systems. The disruption recovery approach used in Munich, Germany - the best service acclaimed by the public, is adopted as the basis to examine whether to collaborate with a taxi company to provide the recovery service and how to price to compensate the service. The two involving parties’ decision functions with the taxi’s average arrival time as the leading decision variable are formulated and analyzed. Both theoretical and numerical sensitivity analyses are conducted to shed lights on the critical factors affecting the decisions.     

The effects of service quality dimensions and passenger characteristics on passenger's overall satisfaction with an airport

The objective of this paper is twofold. First, to identify service quality dimensions related to airports. Second, to examine the effects of those dimensions on passenger's overall satisfaction with an airport together with variables related to passenger characteristics. Data from an extensive survey applied in a main Brazilian international airport were used. Exploratory factor analysis was applied to extract dimensions of airport service quality as perceived by the passengers. The effects on the overall satisfaction level were estimated using a probabilistic approach. Findings underline implications regarding the use of meaningful service dimensions instead of a large set of variables as predictors of passenger satisfaction. Moreover, the study stresses the need for considering how passenger characteristics may be related to different perceived levels of service quality.     

Analyzing the impact of intermodal-related risk to the design and management of biofuel supply chain

This study presents a mathematical model that designs a reliable multi-modal transportation network for a biofuel supply chain system, where intermodal hubs are subject to site-dependent probabilistic disruptions. The disruption probabilities of intermodal hubs are estimated by using a probabilistic model which is developed using real world data. We developed an accelerated Benders decomposition algorithm to solve this challenging NP-hard problem. Numerical analysis show that the model selects to use intermodal hubs located in areas with low disruption probabilities. In case of a disaster, the reliable solution results in 6.21% savings over the minimum cost solution.     

Design of international assembly systems and their supply chains under NAFTA

The purpose of this paper is to provide a decision support aid for the strategic design of an assembly system in the international business environment created by NAFTA. The strategic design problem is to prescribe a set of facilities, including their locations, technologies, and capacities, as well as strategic aspects of the supply chain, selecting suppliers; locating distribution centers; planning transportation modes; and allocating target levels (i.e., amounts) for production, assembly, and distribution. The objective is to maximize after-tax profits. This paper presents a mixed integer programming model that represents the complexities of the international design problem as well as relevant enterprise-wide decisions in the US–Mexico business environment under NAFTA. It deals with a broad set of design issues (e.g., bill-of-material restrictions, international financial considerations, and material flow through the entire supply chain) using effective modeling devices (e.g., linearizing non-linearities that arise in modeling transfer prices and allocating transportation charges). Examples demonstrate how managers might use the model as a decision support aid.     

The impact of market opening on the supply of interregional train services

A stepwise deregulation of all interregional passenger rail services in Sweden was legally completed in 2010. The incumbent operator (SJ) thereby lost the sole rights to commercial services. The most evident supply increase is the establishment of services in the low-cost niche, which rather complements than competes with the incumbent’s supply. Public Transport Authorities’ (PTAs) joint services have however resulted in strong competition on at least one main line.Despite a period of almost five years since deregulation, the potential effects of the market opening have not yet fully materialised. The business risk for commercial rail operators seems to be much greater than for other modes like air and long distance coach services. SJ have also during decades of deregulated intermodal and years of intramodal competition developed their products and skills and seem well prepared for competition.     

The optimization of the closed-loop supply chain network

This paper develops a model of a general closed-loop supply chain network, which includes raw material suppliers, manufacturers, retailers, consumers and recovery centers. The objective of this paper is to formulate and optimize the equilibrium state of the network by using the theory of variational inequalities. Several examples and figures are used to describe the effects of parameters (the return ratio, the transformation rate of raw materials, and the transformation rate of recyclable products) on the equilibrium shipments and net revenues.     

Sustainable design of a closed-loop location-routing-inventory supply chain network under mixed uncertainty

Considering economic, environmental and social impacts, this paper presents a new sustainable closed-loop location-routing-inventory model under mixed uncertainty. The environmental impacts of CO₂ emissions, fuel consumption, wasted energy and the social impacts of created job opportunities and economic development are considered in this paper. The uncertain nature of the network is handled using a stochastic-possibilistic programming approach. Furthermore, for large-sized problems, a hybrid meta-heuristic algorithm and lower bounds are developed and discussed. Finally, a real case study is provided to demonstrate the applicability of the model in real-world applications, and several in-depth analyses are conducted to develop managerial implications.     

The impact of transportation disruptions on supply chain performance

This paper investigates the effect of a transportation disruption on supply chain performance using system dynamics simulation, comparing a traditional supply chain and a vendor managed inventory system (VMI) when a transportation disruption occurs between 2 echelons in a 5-echelon supply chain. The greatest impact occurs when transportation is disrupted between the tier 1 supplier and warehouse. In the traditional structure the retailer, warehouse, and tier 1 supplier experience the greatest inventory fluctuations and the highest goods in transit to their facilities. These impacts are less severe for the VMI structure, although unfilled orders are approximately the same for each.     

Modeling and optimizing the integrated problem of closed-loop supply chain network design and disassembly line balancing

This paper describes an integrated model that jointly optimizes the strategic and tactical decisions of a closed-loop supply chain (CLSC). The strategic level decisions relate to the amounts of goods flowing on the forward and reverse chains. The tactical level decisions concern balancing disassembly lines in the reverse chain. The objective is to minimize costs of transportation, purchasing, refurbishing, and operating the disassembly workstations. A nonlinear mixed integer programming formulation is described for the problem. Numerical examples are presented using the proposed model.     

The demand for public transport: The effects of fares,quality of service,income and car ownership

This paper reports on key findings from a collaborative study whose objective was to produce an up-to-date guidance manual on the factors affecting the demand for public transport for use by public transport operators and planning authorities, and for academics and other researchers. Whilst a wide range of factors was examined in the study, the paper concentrates on the findings regarding the influence of fares, quality of service and income and car ownership. The results are a distillation and synthesis of identified published and unpublished information on the factors affecting public transport demand. The context is principally that of urban surface transport in Great Britain, but extensive use was made in the study of international sources and examples.     

Concurrent design of product family and supply chain network considering quality and price

We study the problem of concurrent design of a product family and its supply chain (SC) network. Inspired by a real-life case in computer industry, the impact of quality and price in SC demand is investigated. Two different models are proposed, the former maximizes the company’s profit with respect to customers’ priorities on quality and price; the latter is a bi-objective programming, which consider two extreme customer groups: for one group quality has the highest priority and for the other price; the intermediate groups falls between these two. The performance of the models is analyzed through a case problem.     

Reliable design of an integrated supply chain with expedited shipments under disruption risks

This paper studied the design of a two-echelon supply chain where a set of suppliers serve a set of terminals that receive uncertain customer demands. In particular, we considered probabilistic transportation disruptions that may halt product supply from certain suppliers. We formulated this problem into an integer nonlinear program to determine the optimal system design that minimizes the expected total cost. A customized solution algorithm based on Lagrangian relaxation was developed to efficiently solve this model. Several numerical examples were conducted to test the proposed model and draw managerial insights into how the key parameters affect the optimal system design.     

The value of information on supply risk under random yields

For companies facing challenge of managing unreliable supply sources, one of the operational goals is to increase the overall profit by improving performance of uncertain supply. We here develop stochastic decision frameworks which evaluate necessary information about uncertainties and help newsvendor and suppliers to enhance supply reliability. We first analyze the newsvendor’s purchasing decision under supply uncertainty and the derived decision framework is used to identify stochastic dominance conditions. We found that partial supply risk information is sufficient to determine regular ordering quantity, but to improve the overall profit, it is important to gather more information about stochastic dominance conditions.     

Dynamics of liner shipping network and port connectivity in supply chain systems: analysis on East Asia

The study of ports in supply chain systems is an emerging area of importance which has drawn more attention from researchers in recent years. This paper presents a new perspective in this research area by examining the calling patterns of container shipping services in order to understand the dynamics of port connectivity and inter-port relationships in the supply chains. Empirical evidence is drawn from four major ports in East Asia, namely Shanghai, Busan, Kaohsiung and Ningbo. The study identifies the shipping capacity, trade routes and geographical regions connected to the ports, shipping lines involved, and the extensity and intensity of inter-port relationships among the four container ports from liner shipping network’s perspective. The findings show that most of the shipping capacity employed on the major east–west trade routes became non-exclusive and involved calls at two or more of the four ports. Port planners, terminal operators and carriers could capitalise on opportunities through exploitation of complementary relationships that exist among the selected ports, such as offering a package for shipping lines to call at a portfolio of terminals owned by the same terminal operator. Policy and research implications as well as recommendations are discussed for various stakeholders concerned with port planning and regional development.     

The value and usage of ticket flexibility for short haul business travellers

Fully flexible business class and “full economy” airline tickets are aimed at meeting the needs of business travellers whose travel requirements may change after a ticket is purchased. The provision of these products has implications for airlines’ revenue management systems, which may lead to overbooking and denied boarding. Low-cost carriers have developed a method by which tickets can be changed only when required. This paper investigates the usage and value of ticket flexibility by business travellers as the popularity of high fare-fully flexible tickets has fallen in recent years. A survey of 284 business travellers showed that business travellers change their flight arrangements in only 32% of short haul trips. A stated preference study investigated the likelihood of respondents to change tickets in three hypothetical scenarios. The results indicate that to extend a business trip for business purposes travellers are confident that their company will bear the cost of changing a ticket valuing additional time at about £54 per hour but that the value of personal time when travelling is fairly low at £15 per hour. The study concludes that business travellers do not need to change their tickets often and that when they do, low-cost carriers offer a more cost-efficient method of providing ticket flexibility. This pay-for-usage approach to ticket flexibility undermines the traditional airlines’ pricing structures and this has contributed to the reduced, relative value of business class and full economy class tickets for short haul air travel.     

Making dynamic ride-sharing work: The impact of driver and rider flexibility

We conduct an extensive computational study to quantify the impact of different types of participants’ flexibility on the performance of a single-driver, single-rider ride-sharing system. Our results consistently show that small increases in flexibility, e.g., in terms of desired departure time or maximum detour time, can significantly increase the expected matching rate, especially when the number of trip announcements in the system is small. The insights gained from our study can provide the basis for the design of information campaigns and incentives schemes aimed at increasing the performance and success of ride-sharing systems.