The container shipping network design problem with empty container repositioning

This paper addresses the design of container liner shipping service networks by explicitly taking into account empty container repositioning. Two key and interrelated issues, those of deploying ships and containers are usually treated separately by most existing studies on shipping network design. In this paper, both issues are considered simultaneously. The problem is formulated as a two-stage problem. A genetic algorithm-based heuristic is developed for the problem. Through a number of numerical experiments that were conducted it was shown that the problem with the consideration of empty container repositioning provides a more insightful solution than the one without.     

Study on China-EU container shipping network in the context of Northern Sea Route

The emerging Northern Sea Route (NSR) represents change to the existing liner network for China-EU container shipping. It is necessary to re-examine the container network in this context and assist liner companies in decision-making. This paper assesses the potential of the NSR based on designing a multi-port multi-trip liner service by establishing a two-stage optimization model. Based on the estimated data of NSR shipping, ship routing schemes on both the NSR and conventional routes are proposed. It is determined that container service along the NSR is largely influenced by ice-breaking charge, seasonality, and cargo volume, which makes NSR more likely to act as a supplementary line of the liner network in the short or medium term. The results also indicate that use of NSR may drive the redeployment of shipping network and hub ports in the long term. This study's conclusions may prove useful for strategic planning by liner companies, port authorities, and governments to assess the operation of liner service via the NSR.     

Liner ship fleet deployment with container transshipment operations

This paper proposes a liner ship fleet deployment (LSFD) problem with container transshipment operations. The proposed problem is formulated as a mixed-integer linear programming model which allows container transshipment operations at any port, any number of times, without explicitly defining the container transshipment variables. Experiments on the Asia-Europe-Oceania shipping network of a global liner shipping company show that more than one third (17-22 ports) of the total of 46 ports have transshipment throughputs. Computational studies based on randomly generated large-scale shipping networks demonstrate that the proposed model can be solved efficiently by CPLEX.     

Simultaneous optimization of schedule coordination and cargo allocation for liner container shipping networks

A liner container shipping carrier usually collects immediately-delivered goods that are produced by manufacturers in world factories, and transports the products to worldwide market destination by offering weekly shipping service. In practice, the carrier has to consider extra demurrage cost of containerized cargos incurred from waiting for weekly shipping service at ports. In this paper, we develop a mathematic programming model to maximize the carrier’s profitability by simultaneously optimizing the ship route scheduling and interrelated cargo allocation scheme. The nonlinear optimization model is transformed into an equivalent mixed-integer linear program, and its applicability is demonstrated by a case study.     

Sailing speed optimization for container ships in a liner shipping network

This paper first calibrates the bunker consumption - sailing speed relation for container ships using historical operating data from a global liner shipping company. It proceeds to investigate the optimal sailing speed of container ships on each leg of each ship route in a liner shipping network while considering transshipment and container routing. This problem is formulated as a mixed-integer nonlinear programming model. In view of the convexity, non-negativity, and univariate properties of the bunker consumption function, an efficient outer-approximation method is proposed to obtain an ε-optimal solution with a predetermined optimality tolerance level ε. The proposed model and algorithm is applied to a real case study for a global liner shipping company.     

A strategic network choice model for global container flows: specification, estimation and application

Container flows have been booming for decades. Expectations for the 21st century are less certain due to changes in climate and energy policy, increasing congestion and increased mobility of production factors. This paper presents a strategic model for the movement of containers on a global scale in order to analyse possible shifts in future container transport demand and the impacts of transport policies thereon. The model predicts yearly container flows over the world’s shipping routes and passing through 437 container ports around the world, based on trade information to and from all countries, taking into account more than 800 maritime container liner services. The model includes import, export and transhipment flows of containers at ports, as well as hinterland flows. The model was calibrated against observed data and is able to reproduce port throughput statistics rather accurately. The paper also introduces a scenario analysis to understand the impact of future, uncertain developments in container flows on port throughput. The scenarios include the effects of slow steaming, an increase in land based shipping costs and an increased use of large scale infrastructures such as the Trans-Siberian rail line and the opening of Arctic shipping routes. These scenarios provide an indication of the uncertainty on the expected port throughputs, with a particular focus on the port of Rotterdam in the Netherlands.     

Reprint of “Enhancing green supply chain initiatives via empty container reuse”

In this paper, the maritime industry’s commitment to green supply chain has been analyzed. The objective of this study is to show that the reuse of empty containers not only adds value to a firm, but leads to waste reduction in the supply chain. The novelties of this article include (i) empty and laden containers are treated in accordance with a shipping company’s green effort; (ii) both the volume and weight of containers are introduced to indicate a potential constraint on green effort; (iii) empty container storage costs are included as a value-added component which stem from green effort.     

A maritime container repositioning yield-based optimization model with uncertain upsurge demand

The role of container repositioning has become more important under the severe cargo shipping environment, affected by world trade growth, trade imbalance, slow steaming strategy and high container manufacturing cost. Low cost, better routing, and supplying equipment to higher yield cargo become the top criteria. A yield-based container repositioning framework is developed, followed by a constrained linear programming optimizing the container repositioning from surplus to deficit locations. The model incorporated change of destinations of empty containers and adjustment factors handling upsurge demand. The model is applied to optimize daily container repositioning operations with a better route, costs and equipment supply.     

A novel hybrid-link-based container routing model

Container routing determines how to transport containers from their origins to their destinations in a liner shipping network. Container routing needs to be solved a number of times as a subproblem in tactical-level decision planning of liner shipping operations. Container routing is similar to the multi-commodity flow problem. This research proposes a novel hybrid-link-based model that nests the existing origin-link-based and destination-link-based models as special cases. Moreover, the hybrid-link-based model is at least as compact as the origin-to-destination-link-based, origin-link-based and destination-link-based models in the literature.     

Multi-port vs. Hub-and-Spoke port calls by containerships

This paper addresses the design of container liner shipping networks taking into consideration container management issues including empty container repositioning. We examine two typical service networks with different ship sizes: multi-port calling by conventional ship size and hub-and-spoke by mega-ship. The entire solution process is performed in two phases: the service network design and container distribution. A wide variety of numerical experiments are conducted for the Asia–Europe and Asia–North America trade lanes. In most scenarios the multi-port calling is superior in terms of total cost, while the hub-and-spoke is more advantageous in the European trade for a costly shipping company.     

Effectiveness of an empty container repositioning policy with flexible destination ports

This paper considers an empty container repositioning policy with flexible destination ports. The policy only specifies the direction of the empty flows, whereas ports of destinations are not determined in advance and empty containers are unloaded from vessels as needed. Interviews with industries show its application in practice, but little research has been reported on its effectiveness. The purpose of the paper is to formulate this policy mathematically and evaluate its effectiveness via simulation. Numerical experiments demonstrate that the new policy outperforms the conventional policy significantly in situations where trade demands are imbalanced and container fleet sizes are within a reasonable range.     

The impact of foldable containers on container fleet management costs in hinterland transport

This paper analyzes the possibility to save container fleet management costs in repositioning empty containers through the use of foldable containers. We model this entire empty container flow as an integer programming problem with different strategies in empty container flow itinerary. The model is used to carry out numerical experiments that optimize the empty container repositioning in the hinterland, where there are serious empty container repositioning problems caused by extremely imbalanced trades. The study finds that foldable containers can substantially save on repositioning costs compared to the use of standard containers.     

Container fleet sizing and empty repositioning in liner shipping systems

This paper considers the joint container fleet sizing and empty container repositioning problem in multi-vessel, multi-port and multi-voyage shipping systems with dynamic, uncertain and imbalanced customer demands. The objective is to minimize the expected total costs including inventory-holding costs, lifting-on/lifting-off costs, transportation costs, repositioning costs, and lost-sale penalty costs. A simulation-based optimization tool is developed to optimize the container fleet size and the parameterized empty repositioning policy simultaneously. The optimization procedure is based on Genetic Algorithms and Evolutionary Strategy combined with an adjustment mechanism. Case studies are given to demonstrate the results.     

The effect of high fuel costs on liner service configuration in container shipping

For shipping activities, not least container shipping, bunker fuel is a considerable expense. In the last 5 years, bunker prices have risen considerably. An increasing bunker price in container shipping, especially in the short term, is only partially compensated through surcharges and will therefore affect earnings negatively. This paper deals with the impact of increasing bunker costs on the design of liner services on the Europe–Far East trade. The paper assesses how shipping lines have adapted their liner service schedules (in terms of commercial speed, number of vessels deployed per loop, etc.) to deal with increased bunker costs. The paper also includes a cost model to simulate the impact of bunker cost changes on the operational costs of liner services. The cost model demonstrates for a typical North Europe–East Asia loop that the current bunker prices have a significant impact on the costs per TEU even when using large post-panamax vessels. The model also shows shipping lines are reacting quite late to higher bunker costs. The reasons that explain the late adaptation of liner services relate to inertia, transit time concerns, increasing costs associated with fixing schedule integrity problems and fleet management issues.     

Urban gravity in the global container shipping network

While the spatial and functional relationships between ports and cities have been put in question in the last decades, the continued importance of urbanization and maritime transport in global socio-economic development motivates deeper research on their interaction. The global trade network is often studied at the country level and all transport modes included, concluding that distance remains a strong counterforce to exchange. This article wishes to detect whether the global container shipping network obeys similar properties at the city level. More than 2 million inter-port vessel movements between 1977 and 2016 are assigned to about 9000 ports and 4600 cities to run a gravity model on two different network topologies. Gravitational properties are found, as larger cities connect more with each other but less at distance. The degree of distance effects negatively expanded in 40 years, confirming the “puzzling” or reinforcing effect of distance, yet it varies greatly depending on node aggregation and network topology. We conclude that ports and cities continue to share important interdependencies, but these often rest on a detrimental physical transformation. A discussion is proposed about the underlying operational and theoretical mechanisms at stake. Keywords container shipping; gravity model; maritime trade; port cities; spatial interaction; world city networks.     

A GRASP algorithm for the container stowage slot planning problem

This work presents a generalization of the Slot Planning Problem which raises when the liner shipping industry needs to plan the placement of containers within a vessel (stowage planning). State-of-the-art stowage planning relies on a heuristic decomposition where containers are first distributed in clusters along the vessel. For each of those clusters a specific position for each container must be found. Compared to previous studies, we have introduced two new features: the explicit handling of rolled out containers and the inclusion of separations rules for dangerous cargo. We present a novel integer programming formulation and a Greedy Randomized Adaptive Search Procedure (GRASP) to solve the problem. The approach is able to find high-quality solution within 1 s. We also provide comparison with the state-of-the-art on an existing and a new set of benchmark instances.     

Levels of internationalization in the container shipping industry: an assessment of the port networks of the large container shipping companies

This paper examines the internationalization level of the world’s largest container shipping companies by examining their port networks. The results of our analysis show that only three of the nineteen companies could be considered as being truly ‘International’ and service the ‘lion’s share’ of the major and minor ports distributed across the globe. The port networks of the other companies in our survey, whilst having individualized features, shared common characteristics. Guided by the ‘Uppsala Model of Incremental Internationalization’ (Johanson and Vahlne, 1977), we were able to identify four internationalization levels of a container shipping company that are indicated by their port network.We argue that the port network plays an additional role as it contributes to the internationalization level of the container shipping companies. This is important because the internationalization level affects the container shipping company’s ability to expand its customer base both at a local and international level. Local customers would have access to a larger international destination network and international customers would be able access a larger local distribution network without transhipping between different companies.Amongst other issues, we were able to determine that, for the analyzed container shipping companies, ‘Internationalization’ of a port network means including or excluding ports in specific regions or sub-regions in their own network, and that a company’s home base or history plays a significant role in this development.     

The effect of multi-scenario policies on empty container repositioning

This paper addresses a container maritime-repositioning problem where several parameters are uncertain and historical data are useless for decision-making processes. To address this problem, we propose a time-extended multi-scenario optimization model in which scenarios can be generated taking into account shipping company opinions. We then show that multi-scenario policies put shipping companies in the position of satisfying empty-container demands for different values that may be taken by uncertain parameters.     

Empty container management for intermodal transportation networks

We present a computational analysis of the effect of planning horizon length on empty container management for intermodal transportation networks. The analysis is based on an integer program that seeks to minimize total costs related to moving empty containers, subject to meeting requirements for moving loaded containers. A case study of potential container-on-barge operations within the Mississippi River basin illustrates the effects of planning horizon length on mode selection. A longer planning horizon can encourage the use of inexpensive, slow transportation modes, such as barge. The impact depends on the number and location of container storage pools.     

Operational shadow pricing in back haul container shipping

Minimum acceptable rates for back haul cargo are difficult for carriers to establish in practice. They depend on complex factors such as availability of empty containers in the vicinity, cost of repositioning empties and container on-hiring decisions. A shadow pricing and “shadow credit” approach is proposed and applied to an inland network. Such a model can help carriers undertake yield management at the operational level to improve financial performance in a post-conference era. Results also suggest a positive relationship between variability in the imbalance situation of laden containers in a particular trade and volatility of short-term back haul freight rates.