Robustness Of Supply Networks Research Articles

Adaptive Variable Neighborhood Search-Based Supply Network Reconfiguration for Robustness Enhancement

Robustness of a supply network highly depends on its structure. Although structural design methods have been proposed to create supply networks with optimal robustness, a real-life supply network can be quite different from these optimal structural designs. Meanwhile, real cases such as Thailand floods and Tohoku earthquake demonstrate the vulnerability of supply networks in real life. Obviously, it is urgent to enhance the robustness of existing real-life supply networks. Thus, in this paper, a supply network reconfiguration method based on adaptive variable neighborhood search (AVNS) is proposed to enhance the structural robustness of supply networks facing both random and target disruptions. Firstly, a supply network model considering the heterogeneous roles of entities is introduced. Based on the model, two robustness metrics, Rr and Rt, are proposed to describe the tolerance of supply networks facing random and target disruptions, respectively. Then, the problem of reconfiguration-based supply network robustness enhancement is described. To solve the problem effectively and efficiently, a new heuristic based on general variable neighborhood search, namely, AVNS, is proposed. Finally, a case study based on three real-life supply networks is presented to verify the applicability and effectiveness of the proposed robustness enhancing method.

An Exploratory Look at Supply Chains in Japan from Multiscale Network Perspectives

In social network analysis, advances in social networking and computing techniques have increasingly become a popular approach for extracting features and rules of real-world networks. The network language— $$G=\{V, E \}$$ provides a common representation of various networks, where G, V, and E denote the system, components, and interactions, respectively. In this study, we employ this emerging technique to discuss supply chains in Japan. We construct the supply network (i.e., system) based on the firms (i.e., components) and their transactional relationships (i.e., interactions). In comparison with the traditional approaches of industrial sectors and regional clusters, this study represents an exploratory look at supply networks, and investigates different scales of supply networks from three perspectives. (1) In the macro-scale perspective, we evaluate the “small-world” separation of supply networks using average path length. (2) In the meso-scale perspective, we detect communities of the supply networks, which can be marked for cross-location and cross-industry features. (3) In the micro-scale perspective, we investigate the “scale-free” nature of supply networks and each community using node degree-prior connections, which can find “hub” firms and simultaneously estimate the robustness of supply networks using a sequential elimination choice strategy of these hubs.

Toward a Theory of Industrial Supply Networks: A Multi-Level Perspective via Network Analysis

In most supply chains (SCs), transaction relationships between suppliers and customers are commonly considered to be an extrapolation from a linear perspective. However, this traditional linear concept of an SC is egotistic and oversimplified and does not sufficiently reflect the complex and cyclical structure of supplier-customer relationships in current economic and industrial situations. The interactional relationships and topological characteristics between suppliers and customers should be analyzed using supply networks (SNs) rather than traditional linear SCs. Therefore, this paper reconceptualizes SCs as SNs in complex adaptive systems (CAS), and presents three main contributions. First, we propose an integrated framework of CAS network by synthesizing multi-level network analysis from the network-, community- and vertex-perspective. The CAS perspective enables us to understand the advances of SN properties. Second, in order to emphasize the CAS properties of SNs, we conducted a real-world SN based on the Japanese industry and describe an advanced investigation of SN theory. The CAS properties help in enriching the SN theory, which can benefit SN management, community economics and industrial resilience. Third, we propose a quantitative metric of entropy to measure the complexity and robustness of SNs. The results not only support a specific understanding of the structural outcomes relevant to SNs, but also deliver efficient and effective support to the management and design of SNs.

State of the Practice: A Review of the Application of OR/MS in Freight Transportation

Freight transportation is an important part of the global supply chain. As distances shipped grow and supply chains become more complex and fragile, operations research (OR) can play an important role in improving the efficiency and robustness of supply networks. This article describes the state of the practice in OR and freight transportation, highlighting recent successful and widely used analytical techniques in oceanic transportation and port operations, and barge, freight rail, intermodal, truckload, less than truckload, and air freight transportation, as well as the use of OR techniques in third-party logistics.

Alleviating the flood risk of critical water supply sites: asset and system resilience

Flooding can have severe impacts on the water supply services and adaptation responses for the provision of high-quality water supplies are necessary to cope with the risks exacerbated by climate change. This paper explores the planning process for adaptation strategies, emphasizing current research and modelling constraints and comparing resilience strategies. The flood hazard, vulnerability and impact were assessed based on information provided by the Environment Agency, local knowledge and network modelling of outages. Improvements in flood estimation were suggested to extend the range of scenarios analysed and the geographic cover and scope of models, whilst reducing and quantifying associated uncertainty. For evaluating consequences of widespread flooding, information on joint flood probabilities would be relevant, particularly where sites are interconnected. Considering the uncertainties in the approach, two strategies were explored to manage the flood risk, i.e. enhanced asset and system resilience. Low-regret options designed to protect a site from flooding were chosen and, where the population at risk is high, those were complemented with long term strategies for increased robustness of supply network to a multiplicity of risks.