Service Network Design Research Articles

Frequency Service Network Design In Freight Transportation Under Integrated Transport System

Nowadays as the integrated transport system is being developed rapidly, how to design service network under the integrated transport system becomes an open issue. Most of the current research literatures in this field fail to integrally consider the transit cost and capacity configuring with different transport modes in the hub node. However, they play important roles for the freight service network design under the integrated transport system. Furthermore, some optimization software such as Lingo and CPlex have been improved significantly recent years. Although their optimization approaches are state-of-the-art, they can’t be carried out directly for reality applications because of the inside disadvantages of the optimization tools. In this paper, we build a service network design frequency model considering the transit cost optimization and capacity configuring with different transport modes. And then, a novel service network design visualization platform is developed based on the C# language of VS2005 and the optimization engine Lingo11. To sum up, this paper not only presents a more effective mathematical model for the problem of freight service network design, but also dynamically uses mature optimization platform to improve the application and practical effect of the algorithm.

A fuzzy AHP based integer linear programming model for the multi‐criteria transshipment problem

PurposeThe purpose of this research is to develop a holistic approach to maximize the customer service level while minimizing the logistics cost by using an integrated multiple criteria decision making (MCDM) method for the contemporary transshipment problem. Unlike the prevalent optimization techniques, this paper proposes an integrated approach which considers both quantitative and qualitative factors in order to maximize the benefits of service deliverers and customers under uncertain environments.Design/methodology/approachThis paper proposes a fuzzy‐based integer linear programming model, based on the existing literature and validated with an example case. The model integrates the developed fuzzy modification of the analytic hierarchy process (FAHP), and solves the multi‐criteria transshipment problem.FindingsThis paper provides several novel insights about how to transform a company from a cost‐based model to a service‐dominated model by using an integrated MCDM method. It suggests that the contemporary customer‐driven supply chain remains and increases its competitiveness from two aspects: optimizing the cost and providing the best service simultaneously.Research limitations/implicationsThis research used one illustrative industry case to exemplify the developed method. Considering the generalization of the research findings and the complexity of the transshipment service network, more cases across multiple industries are necessary to further enhance the validity of the research output.Practical implicationsThe paper includes implications for the evaluation and selection of transshipment service suppliers, the construction of optimal transshipment network as well as managing the network.Originality/valueThe major advantages of this generic approach are that both quantitative and qualitative factors under fuzzy environment are considered simultaneously and also the viewpoints of service deliverers and customers are focused. Therefore, it is believed that it is useful and applicable for the transshipment service network design.

Profit Maximizing Distributed Service System Design with Congestion and Elastic Demand

In this paper we develop a service network design model that explicitly takes into account the elasticity of customer demand with respect to travel distance and congestion delays. The model incorporates a feedback loop between customer demand and congestion at the facilities. The problem is to determine the number of facilities, their locations, their service capacity, and the assignment of customers to facilities so as to maximize the overall profit of the system. Two versions of the problem are presented. In one, each facility is modeled as an M/M/1 queuing system where the service rate is a decision variable; in the other one, the facility is modeled as an M/M/k queuing model where the service rate is given, but the number k is a decision variable. An exact algorithm and heuristics are developed and tested via computational experiments. Although our model is of the “directed choice” type where the assignment of customers to facilities is controlled by the decision maker, computational results show that in the vast majority of cases the customers are assigned to the utility-maximizing facility, indicating that there is no conflict between the customers' and decision makers' goals. A case study of locating preventive medicine clinics in Toronto, Ontario, illustrates the model.

Solving train formation problem using simulated annealing algorithm in a simplex framework

SUMMARYThe train formation plan (TFP) determines the train services and their frequencies and assigns the demands. The TFP models are often formulated as a capacitated service network design problem, and the optimal solution is normally difficult to find. In this paper, a hybrid algorithm of the Simplex method and simulated annealing is proposed for the TFP problem. The basic idea of the proposed algorithm is to use a simulated annealing algorithm to explore the solution space, where the revised Simplex method evaluates, selects, and implements the moves. In the proposed algorithm, the neighborhood structure is based on the pivoting rules of the Simplex method that provides an efficient method to reach the neighbors of the current solution. A state‐of‐the‐art method is applied for parameters tuning by using the design of experiments approach. To evaluate the proposed model and the solution method, 25 test problems have been simulated and solved. The results show the efficiency and the effectiveness of the proposed approach. The proposed approach is implemented to develop the TFP in the Iranian railway as a case study. It is possible to save significant time and cost through solving the TFP problem by using the proposed algorithm and developing the efficient TFP plan in the railway networks. Copyright © 2012 John Wiley & Sons, Ltd.

Robust optimisation approach to the design of service networks for reverse logistics

In this paper we discuss a typical service network of a company providing repair and refurbishment services for its products. To optimise the network we propose a mixed-integer linear programming (MILP) model that minimises the total cost subject to flow balance and logical constraints. The solution of the model determines which facilities are to be used in the network and the associated flows. The model is validated against data obtained from a computer manufacturer and real-life sources. The optimal network configuration depends on several factors such as the number of products returned, percent of faulty products and warranty fraction of modules, which are uncertain in nature. We also address the issue of identifying these uncertain parameters, and their levels to be considered. A min-max robust optimisation model is then developed and solved to address these uncertainties.

Issues and future directions in traffic classification

Traffic classification technology has increased in relevance this decade, as it is now used in the definition and implementation of mechanisms for service differentiation, network design and engineering, security, accounting, advertising, and research. Over the past 10 years the research community and the networking industry have investigated, proposed and developed several classification approaches. While traffic classification techniques are improving in accuracy and efficiency, the continued proliferation of different Internet application behaviors, in addition to growing incentives to disguise some applications to avoid filtering or blocking, are among the reasons that traffic classification remains one of many open problems in Internet research. In this article we review recent achievements and discuss future directions in traffic classification, along with their trade-offs in applicability, reliability, and privacy. We outline the persistently unsolved challenges in the field over the last decade, and suggest several strategies for tackling these challenges to promote progress in the science of Internet traffic classification.

Service network design for freight railway transportation: the Italian case

In this paper, we present a case study on freight railway transportation in Italy, which is a by-product of research collaboration with a major Italian railway company. We highlight the main features of the Italian reality and propose a customized mathematical model to design the service network, that is, the set of origin-destination connections. More specifically, the model suggests the services to provide, the number of trains travelling on each connection, the number of cars and their type. We consider both full and empty freight car movements and take handling costs into account. All decisions are taken in order to minimize the total costs. The quality of service is guaranteed by satisfying all the transportation demand and by implicitly minimizing the waiting time of cars at intermediate railway stations. Our approach yields to a multi-commodity network design problem with a concave cost function. To solve this problem, we implement a specialized tabu search procedure. Computational results on realistic instances show a significant improvement over current practice.

Tabu assisted guided local search approaches for freight service network design

The service network design problem (SNDP) is a core problem in freight transportation. It involves the determination of the most cost-effective transportation network and the characteristics of the corresponding services, subject to various constraints. The scale of the problem in real-world applications is usually very large, especially when the network contains both the geographical information and the temporal constraints which are necessary for modelling multiple service-classes and dynamic events. The development of time-efficient algorithms for this problem is, therefore, crucial for successful real-world applications. Earlier research indicated that guided local search (GLS) was a promising solution method for this problem. One of the advantages of GLS is that it makes use of both the information collected during the search as well as any special structures which are present in solutions. Building upon earlier research, this paper carries out in-depth investigations into several mechanisms that could potentially speed up the GLS algorithm for the SNDP. Specifically, the mechanisms that we have looked at in this paper include a tabu list (as used by tabu search), short-term memory, and an aspiration criterion. An efficient hybrid algorithm for the SNDP is then proposed, based upon the results of these experiments. The algorithm combines a tabu list within a multi-start GLS approach, with an efficient feasibility-repairing heuristic. Experimental tests on a set of 24 well-known service network design benchmark instances have shown that the proposed algorithm is superior to a previously proposed tabu search method, reducing the computation time by over a third. In addition, we also show that far better results can be obtained when a faster linear program solver is adopted for the sub-problem solution. The contribution of this paper is an efficient algorithm, along with detailed analyses of effective mechanisms which can help to increase the speed of the GLS algorithm for the SNDP.

The Research on Railway Luggage & Package Shipping Plan Based on Service Network

Due to the particularity of railway luggage & package shipping organization and large requirement of luggage & package shipping, the problem of making luggage & package shipping plan is increasingly complex. In order to improve the efficiency of making luggage & package shipping plan and assist human work, this paper mainly discusses how to optimize the plan. Based on analyzing the characteristic of luggage & package shipping, this paper analyzes lots of factors that affects the rationality of the plan and establishes an optimization model with the objective of minimizing general cost based on service network, and then develops a Heuristic Algorithm. At last, the application of service network design model for luggage & package shipping and its solution approach are illustrated with the case.

Design of Service Network of Huachuan Denso Co.

Location decision of Service Networks is important for an enterprise to dominate market and to improve service level. Characteristics and the decentralized control strategies of service network were discussed for the enterprise of Denso class. A 0-1 mixed integer programming model was established for location problem of spare parts centers and solved by ILOG along with sensitivity analysis. Furthermore, a dynamic programming model was established for location problem of sales model shop and calculated by a numerical listing method.

Corridor network design in hinterland transportation systems

In this paper the design of the service network in intermodal barge transport is studied. The network of inland barge terminals is modelled to demonstrate potential cooperations in a corridor network. Cooperation between inland terminals leads to bundling of freight flows in the hinterland of major ports. A service network design model for intermodal barge transport is developed and applied to the hinterland network of the port of Antwerp in Belgium. Selected cooperation schemes are simulated by means of a discrete event simulation model for intermodal barge transport and compared with simulation results of bundling in the port area. Cooperation between inland terminals offers an opportunity to attain economies of scale, but may not be perceived as a sole solution for reducing waiting times of inland barges at sea terminals. A combination of bundling measures in the port area and in the hinterland may be necessary to improve the intermodal transport chain.

Liner shipping service network design with empty container repositioning

This paper proposes a liner shipping service network design problem with combined hub-and-spoke and multi-port-calling operations and empty container repositioning. It first introduces a novel concept – segment – defined as a pair of ordered ports served by one shipping line and subsequently develops a mixed-integer linear programming model for the proposed problem. Extensive numerical experiments based on realistic Asia–Europe–Oceania shipping operations show that the proposed model can be efficiently solved by CPLEX for real-case problems. They also demonstrate the potential for large cost-savings over pure hub-and-spoke or pure multi-port-calling network, or network without considering empty container repositioning.

Branch and Price for Service Network Design with Asset Management Constraints

We address the service network design problem with asset management considerations for consolidation-based freight carriers. Given a set of demands to be transported from origins to destinations and a set of transshipment facilities, the objective is to select services and their schedules, build routes for the assets (vehicles) operating these scheduled services, and move the demands (commodities) through the resulting service network as efficiently as possible. We propose a first branch-and-price framework for the mixed-integer formulation of the problem with integer cycle design and continuous flow-path variables. The proposed method includes particular column generation subproblems for dynamically constructing these cycles and paths, as well as an acceleration technique to identify integer solutions rapidly. The computational study shows that the proposed method finds better solutions for large network instances than reported previously.

Simulation and optimisation of intermodal barge transport networks

This is a summary of the author’s PhD thesis supervised by Gerrit Janssens and Cathy Macharis and defended on 7 May 2010 at the Hasselt University, Belgium. The thesis is written in English and is available from the author upon request. This work deals with two key aspects in the competitiveness of intermodal transport making use of inland navigation. The first part of the thesis studies bundling of freight in intermodal barge transport networks. Alternative bundling strategies for container barge transport are compared by means of discrete event simulation. Cooperation between inland barge terminals to bundle freight flows is modelled as a service network design problem. The second part relates to the initial and final journey by road in the intermodal barge transport chain. Pre- and end-haulage by road is modelled as a Full Truckload Pickup and Delivery Problem with Time Windows. A local search algorithm and deterministic annealing algorithm are proposed to find near-optimal solutions.

Profit-based reconfiguration of express courier service network with multiple consolidation terminals

The design of an express service network is determined by considering the amount of initial investments and operating costs for terminals and service centres within the network. However, continuous modifications of network design are required to adjust to rapidly changing business environments. This study suggests an approach to the reconfiguration of an express courier service network with respect to assignments of service centres to consolidation terminals, adjustments of their cutoff times, and extensions of terminal capacities. We propose an integer programming model and a genetic algorithm based solution procedure for allowing express couriers to maximise their incremental profit. An illustrative numerical example with reduced data sets from an express courier in Korea is presented to demonstrate the practicality and efficiency of the proposed model and its solution procedure.

Service Networks Topological Design

Topological design of service networks is studied in the paper. Quantitative model and algorithm minimizing cost of processing and delivery is described. Algorithm solving combinatorial problem of optimal design based on binary partitioning, a parametric search and dynamic programming optimization of a binary tree is described and demonstrated in numeric example.

A decomposition scheme for large-scale Service Network Design with asset management

In this paper, we address a large-scale freight transportation problem for maximizing the profit of a carrier. We propose two solving algorithms using a decomposition of the problem into three main steps: construction of the network, filling vehicles with commodities and construction of the vehicle plannings. The resolution of these steps involves heuristic schemes, Mixed Integer Programming and Constraint Programming techniques. To evaluate the model and the solution algorithms, we produce instances based on a study of real-life data. The results show that the methods without transhipment provide solutions with a good computation time/quality trade-off.

A metaheuristic for stochastic service network design

This paper considers the time-dependent service network design problem with stochastic demand represented by scenarios. To our knowledge, this is the first attempt to address real life-size instances of this problem. The model integrates the balancing of empty vehicles, the cost of handling freight in intermediate terminals, the costs associated with moving freight using the selected services, and the penalty costs of not being able to deliver freight. A metaheuristic is presented and computational results are reported on a set of large new problem instances.

Large-Scale, Less-than-Truckload Service Network Design

We present a novel formulation for the service network design problem in the context of large-scale, less-than-truckload (LTL) freight operations. The formulation captures the basic network design constraints; the load-planning requirement that all freight at a location, irrespective of the freight's origin, loads to the same next terminal; and other important LTL-specific requirements. Our modeling scheme fragments the underlying massive network design model with up to 1.3 million 0–1 variables and 1.3 million rows into a separate and efficient integer programming (IP) problem for each destination terminal along with a coordinating master network design problem. We produce high-quality solutions in very reasonable CPU times (∼2 hours) using slope scaling and load-planning tree generation with corresponding potential annual savings of $20–25 million dollars for the target company for which the research was conducted.

Models and Tabu Search Metaheuristics for Service Network Design with Asset-Balance Requirements

This paper focuses on a generic model for service network design, which includes asset positioning and utilization through constraints on asset availability at terminals. We denote these relations as “design-balance constraints” and focus on the design-balanced capacitated multicommodity network design model, a generalization of the capacitated multicommodity network design model generally used in service network design applications. Both arc- and cycle-based formulations for the new model are presented. The paper also proposes a tabu search metaheuristic framework for the arc-based formulation. Results on a wide range of network design problem instances from the literature indicate the proposed method behaves very well in terms of computational efficiency and solution quality.