Optimization of empty container movements using street-turn: Application to Valencia hinterland

With the global container population exceeding 25 million TEU (Twenty-foot Equivalent Unit) and the annual production of new boxes exceeding 3 million TEU it is estimated that around 1.5 million TEU of empty containers are sitting in yards and depots around the world waiting for use. Although utilization rates have improved since 2004, container utilization depends on the very dynamic nature of container transportation, and the container building and leasing industries. Owing primarily to the chronic trend of increasing trade imbalances across the oceans, and despite recent trends along some trade routes, the empty container management problem has become a major issue for the container shipping industry during the last decade. This paper examines and analyzes empty container logistics at a global, interregional, regional and local level. Special consideration is given to key factors affecting the empty container logistics management and strategies implemented by ocean carriers and other stakeholders to better manage empty containers.

Empty container management deals with repositioning empty containers at minimum costs while fulfilling empty container demands. Due to imbalances in trade, some areas have a surplus of empty containers, while others have a shortage. Therefore, empty containers need to be repositioned globally to make sure that sufficient empty containers are available everywhere. Besides, empty containers need to be repositioned regionally between shippers, consignees, inland depots, terminals and ports in order to fulfil demand. In this paper, the focus is on the empty container management problem at a regional level. The problem is described in detail and opportunities for reducing empty container movements are discussed. Decisions to be taken at each planning level (strategic, tactical and operational) are described, and for each planning level, a detailed overview of planning models proposed in the literature is presented. Planning models considering decisions at several planning levels are discussed as well. Finally, interesting opportunities for future research are identified.

In recent decades, the rapid development of international economy has led to significant inter-regional trade imbalances. In marine transportation, the voluminous empty containers accumulated at ports in import dominated countries have to be re-circulated back to ports in export dominated countries for re-deployment. This repositioning of empty containers is crucial for shipping companies to provide effective transportation services. At present, empty container repositioning has proved to be highly expensive, contributing to 27% of the overall operation cost of shipping companies. Consequently, major stakeholders including the shipping companies have strived to reduce the repositioning cost. Unfortunately, few major improvements have been made over the years and there are still lingering research issues. The objective of this research, therefore, is to develop efficient and effective methodologies to obtain empty container repositioning plans that can significantly reduce transportation cost while fulfilling customer demands of empty and laden containers.
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\nIn this research, the empty container repositioning problem under two related real marine transportation scenarios has been studied. The first scenario considers multi-vessel transportation for both laden and empty containers with split vessel routing (denoted as ECRSVR). A mathematical model of ECRSVR is developed based on the formulation of the Pickup and Delivery Problem with Time Windows (PDPTW). However, a major research issue arises due to such integrated consideration of split vessel routing and transportation of empty and laden containers. The resulting model will encompass many more new decision variables and constraints. Thus, it cannot be readily solved by existing algorithms. To address this issue, a new Branch-and-Price (B&P) algorithm incorporating B&B and column generation is developed. Specifically, a new dynamic programming algorithm with new label structure and dominance rules is established to solve the pricing problem in B&P, and a new multi-layer branching scheme is developed for implementing the algorithm. The effectiveness and robustness of the proposed methodology are then tested on a set of randomly generated problems.
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\nThe second scenario extends the first by including transshipment activities in the ECRSVR (denoted as ECRSVRTS). Apparently, the inclusion of transshipment activities will significantly increase the size of the solution space of feasible routing and distribution schemes. Also, more constraints have to be included in the model to account for the interdependence between the distribution schemes of separate vessels. To tackle this problem, two mathematical models are developed. The first is a port-based model that explicitly characterizes the routing plans and distribution volumes for each vessel at each time interval as decision variables. The resulting integer program is non-linear and difficult to solve. Therefore, an equivalent event-driven node-based model inspired by the formulation of PDPTW is constructed. In this model, the pickup/delivery tasks and transshipment events are represented as nodes in a generated topology. The B&P scheme is then modified to solve the node-based model and a Hybrid Scatter Tabu Search (HSTS) is developed to solve the pricing problems. Results obtained from the numerical experiments using randomly generated test problems show that the proposed HSTS algorithm outperforms conventional scatter search and tabu search algorithms.

Application of a mixed fuzzy decision making and optimization programming model to the empty container allocation

Container drayage, as a pivotal element of door-to-door intermodal transportation, has garnered increasing attention due to its significant influence on container logistics costs. Although various types of transport requests have been defined in the literature, no comprehensive study has addressed all of them together yet, due to the lack of an efficient model and corresponding algorithms. Furthermore, existing research on container drayage often neglects the simultaneous incorporation of two trucking operation modes, two empty container repositioning strategies, and the availability of empty containers across multiple depots. To address these issues, this study proposes a comprehensive container drayage problem (CDP) and mathematically formulates it as an innovative mixed integer linear programming (MILP) model, capturing the uncertainty and unpredictability inherent in empty container allocation, truck dispatching, and route planning. Given the problem’s complexity, obtaining an exact solution for large instances is not feasible. Therefore, an improved large neighborhood search (LNS) algorithm is tailored by incorporating the “Sequential insertion” and the “Solution re-optimization” operations. Extensive numerical experiments using randomly generated instances of varying scales validate the correctness of the proposed model and demonstrate the performance of the proposed algorithm. Additionally, sensitivity analysis on the number and distribution of depots and empty containers offers valuable managerial insights for the development of an effective container drayage system.

Only 13% of Brazilian loads are transported by ships, which does not match the reality of its territory, where its extensive area and coastline make the waterway mode an important alternative in cargo handling. In this context, the present work aims to simulate a short sea shipping system where ships circulate between three dedicated ports, located in Suape, Santos and Rio Grande, in order to size the number of berths per port and the number and size of the ships necessary to transport, exclusively by containers, a portion of the road load. The work considers the pre-operation, operation (loading and unloading), post-operation, travel between ports and eventual entry queues, in a stochastic approach of these factors, and beside that the balancing and movement of empty containers. The results show that the infrastructure size required for the implementation of a short sea shipping system is feasible and would be an alternative to improve the system of cargo transportation among the states studied.

An artificial intelligence-based system was developed to efficiently predict settling velocity (SV) using a large dataset comprised of 2726 samples. The ranges of particle size and fluid viscosity were 0.212 − 98.59 mm and 0.02 − 92800 mPa.s, respectively. Properties of particle and fluid were fed to a model as the inputs to obtain SV as the output. Six machine learning algorithms were tested for the prediction. The random forest (RF) performed better than other algorithms with a coefficient of determination of 0.98 and a mean square error of 0.0027. A simple decision support system was developed using the RF model. The current study demonstrates the complete methodology of modeling SV with ML.

Spatial dynamics of metropolitan development are becoming important issues in sustainable development. In developing countries like Indonesia, the growth of metropolitan regions is often followed by problems of unsustainability. Therefore, a framework of assessment for metropolitan development can be useful as an early means of identifying any untoward aspects. This study aims to develop an assessment system that is easily applicable (user-friendly) in assessing metropolitan development in Indonesia. It is a Geographic Information System (GIS)-based spatial model formulated as a simple Decision Support System (DSS), within which information can be queried down to district (kecamatan) level. As a test case, the model was applied in the Semarang Metropolitan Region of Central Java. The results show that it is capable of documenting and assessing the level of sustainability of the region. However, the lack of data at the kecamatan level is the main barrier to the application and development of the technique. Consequently, an in-depth study involving intensive dissemination of the concept, initiative and promulgation of initial results is subsequently proposed so that awareness of the local decision makers of the Indonesian government can be improved.

Simulation-Optimization Model in Managing the Empty Container Movements Problem through Repositioning Strategies

This paper focuses on the regional empty container repositioning problem. We propose a more practical model to optimize regional empty container movements. With the framework, we evaluate the effectiveness of “street-turn” strategy and provide insights on “street-turn” operation in Metro Vancouver area. We conduct interviews with local industry professionals to collect information about current empty container operations. The major findings from this research are: (1) “Street-turn” strategy reduces empty container repositioning cost majorly from transportation and gate fees. (2) “Street-turn” strategy is more effective in trade-balanced environment than trade-imbalanced environment. (3) The number of participants in the transport network has a positive impact on the feasibility and effectiveness of “street-turn” strategy. (4) The variance in the supply and demand of empty containers increases the variance in the effectiveness of “street-turn” strategy. (5) Container users have higher incentive to promote “street-turn” operations than shipping lines. (6) “Street-turn” strategy has been conducted jointly by a few importers and exporters in Metro Vancouver area. The major challenge is that container information is not shared among participants. (7) Unlike the situation in LA/LB port region, shipping lines have not yet taken the initiative to promote “street-turn” interchanges in Metro Vancouver area. The successful implementation of “street-turn” strategy depends on the participation of each player. With a high level of information visibility, the proposed model can be employed as a decision support tool to identify “street-turn” opportunities and optimize empty container movements within the system.

Problem statement: Empty containers are an essential part of the logi stics of the movement, repositioning and distribution of contain ers. Optimizing the allocation and transportation o f empty containers contributes significantly in reduc ing cost. Approach: A mathematical model is formulated with the objective of finding an optimal sequence of ships movement among ports in order to satisfy demands at the ports with minimum total cost. Results: Several numerical examples are used to compare the performance of the developed optimization model with well known standard models available in the literature. C onclusion/Recommendation: It was observed that the solution obtained by the developed method to be either as good as or better than the solution provided by other standard models. Future work should consider contribution of full containers in meeting demand for empty containers.

Abstract: Technology is a tool for processing, storing and modifying data to obtain informatio. Decision Support System (DSS) a based model-based with data processing procedures and considerations to assist manager in decision making. In the context of UD.Wendy Jaya which still uses manual methods for selecting superior cement, this is considered less effective and ineffcient, resulting in cement selection that does not meet the criteria and lacks accuracy. This research employs a quantitative method with the aim of determining decisions for selecting superior cemen and designing a decision support system using the Simple Additive Weighting (SAW) method based on predetermined criteria. The implementation result show that the decision support system for determining superior cement provides convenience and speed in selecting superior cement at UD Wendy Jaya according to the expected criteria. The results of calculations using the simple additive weighting (SAW) method rank each alternative, with the most superior alternative being three-wheel cement, considering several criteria such as price, compressive, strength, fineness, water capacity and setting time.Keywords: simple additive weighting (SAW); decision support system; UD.wendy jayaAbstrak: Teknologi adalah alat untuk mengolah, menyimpan, dan memodifikasi data guna mendapatkan informasi. Sistem Pendukung Keputusan (Decision Support System/DSS) merupakan sistem berbasis model dengan prosedur pemrosesan data dan pertimbangan untuk membantu manajer dalam pengambilan keputusan. Dalam konteks Toko UD. Wendy Jaya, yang masih menggunakan cara manual untuk pemilihan semen unggul, hal ini dianggap kurang efektif dan tidak efisien, mengakibatkan pemilihan semen tidak sesuai kriteria dan tidak akurat. Penelitian ini menggunakan metode kuantitatif, dengan tujuan untuk mengetahui keputusan pemilihan semen unggul dan merancang sistem pendukung keputusan menggunakan metode Simple Additive Weighting (SAW) berdasarkan kriteria yang ditentukan. Hasil implementasi menunjukkan bahwa sistem pendukung keputusan Menentukan Semen Unggul memberikan kemudahan dan kecepatan dalam pemilihan semen unggul pada Toko UD. Wendy Jaya sesuai dengan kriteria yang diharapkan. Hasil dari perhitungan dengan menggunakan metode Simple Additive Weighting (SAW) adalah perangkingan setiap alternatif yaitu diperoleh alternatif yang paling unggul adalah semen tiga roda ditinjau dari beberapa kriteria harga, kuat tekanan, kehalusan, kapasitas air dan waktu mengeras.Kata kunci: simple additive weighting (SAW); sistem pendukung keputusan; UD.wendy jaya

Container logistics and empty container repositioning

In a rapidly changing world, most operational processes of enterprises are conducted in the form of development projects. The development of new products is an important organizational strategy to meet consumer needs. During this process, enterprises often encounter many bottlenecks and risks that can cause delays in, and even the failure of, development projects. In this study, we developed a research framework based on relevant literature and expert interviews and then used the decision making trial and evaluation laboratory (DEMATEL) and the analytic network process (ANP) to determine the relationships among and the importance of risks in the development of new products. The results of a case study show that the six key risks of product development projects include project completion time, mastery of key technical capabilities, controlling the progress of the project, uniqueness and complexity of the project, ability to control the market, and functional integrity of the product. According to the results of importance performance analysis, six key factors were classified in the concentrate quadrant. The optoelectronic manufacturing industry should focus on reducing risks to the project. A cause-and-effect diagram shows that if an enterprise wants to improve performance in terms of these key factors, it should first improve the project completion time or the mastery of key technical capabilities. Therefore, it is appropriate to start by improving the project completion time. In this study, we developed a practical and simple decision support system that allows managers of research and development to examine the risk of projects and assess the relevant risks. A case study was also conducted to test the accuracy of the proposed risk-management method.

Land subsidence is mapped over two Danish coastal study locations from precision leveling and modified Sentinel-1 satellite data. Geological models are produced after digitization of geotechnical archives. The inferred subsidence patterns are related to the geology and advantages of bringing this information together in flood risk assessments and in climate adaptation are discussed. The lack of data for subsidence monitoring and a fragmentation of geotechnical information are considered a hindrance to optimal adaptation measures in Denmark. A national subsidence mapping to gain an overview of the challenges faced is advocated. A simple decision support system can implement subsidence and geotechnical information in coastal climate adaptation to the benefit of municipalities and other relevant stakeholders.