Supply Chain Problem Research Articles

Distributional reinforcement learning for inventory management in multi-echelon supply chains

Reinforcement Learning (RL) is an effective method to solve stochastic sequential decision-making problems. This is a problem description common to supply chain operations, however, most RL algorithms are tailored for game-based benchmarks. Here, we propose a deep RL method tailored for supply chain problems. The proposed algorithm deploys a derivative free approach to balance exploration and exploitation of the neural policy’s parameter space, providing means to avoid low quality local optima. Furthermore, the method allows consideration of risk-sensitive formulations to learn a policy that optimizes, for example, the conditional value-at-risk. The capabilities of our algorithm are tested on a multi-echelon supply chain problem, and several combinatorial optimization problems. The results empirically demonstrate the method’s improved sample efficiency compared to the benchmark algorithm proximal policy optimization, and superior performance to shrinking horizon mixed integer formulations. Additionally, its risk-sensitive policy can offer protection from low probability, high severity scenarios. Finally, we provide a sensitivity analysis for technical intuition.

Key Factors That Can Enable Transparency in the Volatile Agri-Food Supply Chain

There are few industries more crucial to the global economy than agriculture. The economic well-being, security, and health of a nation's population all depend on its agricultural economy. These days, people are paying a lot more attention than ever before to issues related to food insecurity. Few industries are profitable as the global food supply chain. Unfortunately, the data illustrates that there are problems in the food supply chain. The failure rate of the Agri-food Supply Chain (ASC) is much higher because of the information gap caused by the difficulty of end-to-end traceability. Therefore, it is now crucially important to monitor ASC with the components. Literature review concludes that consumers' health can be significantly improved by using Blockchain database and Internet of Things (IoT) technologies to track the provenance of their food in real-time. With the help of these innovations, the entire agricultural product supply chain, beginning with the farmers and ending with the retailers, can be handled with complete transparency. Through the use of IoT, food can be traced, verified, inspected for quality and security, inventoried, food waste managed, and eventually, the data may be secured in a database and made available to all through blockchain. The price of the product and the supply of a safe and transparent payment chain for all parties involved in the agri-food supply chain are other crucial elements. Therefore, Agri- Food Supply Chain (ASC) transparency may be ensured with the help of IoT technology, a blockchain database system, and safe and automated financial flow.

A Quantum-inspired Ant Colony Optimization for solving a sustainable four-dimensional traveling salesman problem under type-2 fuzzy variable

In this paper, a Quantum-inspired Ant Colony Optimization (Qi-ACO) is proposed to solve a sustainable four-dimensional traveling salesman problem (4DTSP). In 4DTSP, various paths with a different number of conveyances are available to travel between any two cities. In this model, we have considered a sustainable 4DTSP in terms of emission as a constraint. Since travel costs and emissions are uncertain/imprecise in nature, so here we consider type-2 variables. Sustainable development in the traveling salesman problem (TSP) sector can be divided into two major sections: economy and environmental. Sustainable TSP development requires balancing to achieve the maximum benefits for these two sectors. For increasing development in sustainable transportation, we need to use some strategies for increasing sustainability. These strategies include improving route and vehicle selection, routing plan, vehicle speed, etc. The novelties of the proposed Qi-ACO algorithm are (i) Qubit generated based on the amount of emission of the vehicle as well as travel cost between two cities, (ii) pheromone initialized and updated depends on the qubit, (iii) quantum-inspired technique makes fast computation. The proposed sustainable 4DTSP is illustrated with some numerical data. The defuzzification of type-2 fuzzy variable based on the Critical value (CV) method is used in this model. The supremacy of the proposed method is established through some statistical tests. The proposed algorithm and its modified form can be easily adapted in ship routing, supply chain problems, and other fields.

Co-Opetition Strategy for Remanufacturing the Closed-Loop Supply Chain Considering the Design for Remanufacturing

The co-opetition strategy between manufacturers and remanufacturers is a key problem of the closed-loop supply chain, especially for the manufacturers often facing decision-making dilemmas when undertaking the environmental responsibilities of the design for remanufacturing (DfRem). Since DfRem is thought to be advantageous for recycling and remanufacturing, it will lower the production costs for remanufacturers but raise them for manufacturers. On the other hand, manufacturers cannot abandon the DfRem because of environmental responsibilities. This work thus formulates three two-period game models of the competition model with patent protection, the competition model without patent protection, and the cooperation model, which consists of a manufacturer and a remanufacturer, to investigate the decision of the manufacturer and remanufacturer co-opetition strategies. The price, the level of DfRem, the recovery rate, the profit, and other factors are compared across the three models using reverse induction and numerical simulation. In addition, we analyzed the influence of different equilibrium solutions on customer willingness to pay for remanufactured products. We find that cooperation not only contributes to the improvement of DfRem but is also the best choice to ensure the stable development of the supply chain system. Manufacturers, in particular, prefer to work together wherever feasible and actively pursue collaboration rather than advocating for patent protection to fend against remanufacturers, even when they have patent rights.

An Efficient Imperialist Competitive Algorithm for Solving Location Routing Problem in the Multi-Level Supply Chain Under Fuzzy and Probabilistic Condition

در دنیای صنعتی امروز، واحدهای تولیدی سعی دارند با مکان‌یابی مناسب انبارهای مورد نیاز خود و همچنین مسیریابی وسایل نقلیه به‌منظور حمل کالاهای تولیدی به این انبارها، هزینه‌های خود را کاهش دهند. لازم به‌ ذکر است که، مکان انبارها درتعیین مسیر وسایل نقلیه موثر است. بنابراین در این مقاله، یک مدل برنامه‌ریزی ریاضی جهت بهینه‌سازی هم‌زمان تعیین مکان انبارها و مسیریابی وسایل نقلیه ارائه شده-است. تابع هدف در این مدل شامل مینیمم‌کردن مجموع هزینه‌های مرتبط با وسایل حمل‌و‌نقل و هزینه‌ی اجاره انبارها می‌باشد. محدودیت‌های مدل ارائه شده شامل ظرفیت وسایل نقلیه، حداکثر میزان مسافت طی شده توسط وسایل نقلیه و ... می‌باشد. از آنجایی‌که هریک از مسایل مکان‌یابی و مسیریابی خود به تنهایی یک مسأله NP-hard محسوب می‌شوند، آنگاه مسأله مکان‌یابی- مسیریابی نیز یک مسأله NP-hard ترکیبی محسوب می‌شود و برای حل آن نیاز به بهره‌گیری از الگوریتم‌های فراابتکاری می‌باشد.

Incorporating a choice-based diffusion model into a bi-objective multi-generation product optimization problem under consignment stock policy

Rapid changes and evolution in technological innovation have spilled over many industries and compelled firms to release new products periodically. The advent of new products intensifies the importance of analyzing sales data trends and finding the most profitable portfolio that can no longer be ignored in production planning. The topic of diffusion processes has evoked considerable interest from academics and practitioners to forecast sales patterns of two or three competitive generations. However, there is still a lack of in-depth discussion on the effects of core determinants on customers' preferences and choices. This paper bridges the gaps in the literature by conceptualizing the interaction effects among current and new products on diffusion processes that could affect supply chain operations. Specifically, the Bass diffusion model (BDM) is modified to estimate market volume, advertisement effects, and sales data trends, then combined with a choice model to examine how consumers' propensities affect the choice probability of alternatives. The proposed choice-based diffusion model is incorporated into a supply chain problem for joint planning on a production-location-inventory problem concerning the economic and social aspects of designing multi-generation production lines. The model formulation is a bi-objective mixed-integer nonlinear problem with a computation burden. Thus an outer approximation-based algorithm is proposed to reduce computational complexity and combined with an augmented ε-constraint to generate efficient Pareto sets. The model is validated by conducting a case study in Iran and compared to other established models. The computational results demonstrate the proposed model outperforms the expert forecasts, and there are no significant differences between the total sales estimated by the proposed model and the actual sales. The manager is advised to adopt a conscious policy for adoption engagement under supply constraints. It should price the products in a way be more tightly aligned with customers’ desirability and overcome the supply constraints by increasing production or storage capacities.

Decision Analysis of Manufacturer-Led Closed-Loop Supply Chain Considering Corporate Social Responsibility.

With the rapid development of the economy, a growing number of consumers and enterprises are paying attention to corporate social responsibility (CSR). Meanwhile, there exist a variety of conflicts in closed-loop supply chain management. To analyse and deal with the decision problems of the manufacturer-led closed-loop supply chain with CSR, by using the manufacturer Stackelberg game, we construct some basic models considering CSR, and exploit them to analyse the optimal decisions of supply chains with and without CSR under centralized and decentralized decision making and explore the influence of CSR on supply chain, and then we establish a coordination mechanism through two-part tariff.

Dynamic Cooperation of the O2O Supply Chain Based on Time Delays and Bidirectional Free-Riding

Advertising and service investment can enhance brand goodwill to increase the sales of branded goods. However, the impact of advertising and services on brand goodwill is not immediate but delayed. At the same time, due to the different service characteristics provided by various channels, the phenomenon of bidirectional free-riding occurs. Therefore, this paper studies the dynamic cooperation between service and advertising in the O2O (online to offline) supply chain dominated by brand owners and explores the impacts of advertising, service delay and service free-riding among channels on the dynamic cooperation decisions of the O2O supply chain. A differential game model between brands and retailers is constructed by incorporating the delay effect and the bidirectional free-riding phenomenon. The optimal advertising and service strategies and performance problems of O2O supply chain enterprises under a centralized decision, brand cost-sharing decision and bilateral cost-sharing decision are compared and analyzed. The influence of delay time, showrooming and webrooming effects on the profit of each firm is investigated by example. The results show that the service strategy, advertising strategy and brand goodwill of the O2O supply chain members are optimal under a centralized decision. Still, the supply chain profit is not necessarily optimal under the delay time, showrooming and webrooming effect coefficients. Bilateral cost-sharing contracts can achieve Pareto improvement of supply chain performance. Appropriate setting of a bilateral cost-sharing ratio can adjust the adverse effects of delay and bidirectional free-riding. The long-term strategies to deal with the delay and bidirectional free-riding phenomena are as follows: the bilateral cost-sharing contract can improve corporate profits. Setting the wholesale price, online direct-selling price and service-sharing ratio by brand owners can effectively promote retailers’ investment in service, achieving a win-win situation. Retailers maintain high pricing and service levels to enhance the brand premium ability of physical stores and achieve long-term development.

Review of Strategic Agility: A Holistic Framework for Fresh Produce Supply Chain Disruptions

The influence of the rapidly changing business environment due to the COVID-19 global pandemic presents an important organizational challenge to fresh produce export supply chains in developing countries such as Ghana. Such an inimical supply chain problem highlights the relevance of supply chain agility as a potent methodological framework to measure, monitor and evaluate these challenges in stable as well as turbulent times. This review paper focuses on the applicability of a framework for Supply Chain Agility as a methodological framework in stable (pre-COVID-19) versus turbulent (COVID-19) business environments. We argue and propose that Supply Chain Agility Framework is a holistic framework which is efficacious in both stable and unstable supply chain environments. This is amply supported by the central plank of our proposition that the Supply Chain Agility Framework offers an adaptable tool that can serve as a panacea to fresh produce supply chain challenges not only in a stable (pre-COVID-19) business environment but also effective and applicable in a turbulent business environment, such as experienced during the COVID-19 pandemic. The implications of this proposition for the fresh produce export supply chain industry and relevant stakeholders are duly presented.

Land-use and food security in energy transition: Role of food supply

Food security in a just energy transition is a growing debate about designing sustainable food secure networks worldwide. Energy transition, land-use change, and food security are crucial factors for food security and provision. The increased demand for food products and customer preferences regarding food safety provide various issues for the current agriculture food supply chain (AFSC). Along with rising sustainability concerns, strict government regulation, food security, and traceability concerns compel managers, business houses, and practitioners working in AFSC to adopt new tools, techniques, and methodologies to model current food supply chain problems. Thus, in turn, design the food logistics network for food security. Hence, this study investigates the core determinants of food security and supply in Egypt, Morocco, Tunisia, and Lebanon over the period of 2010–2019. In order to estimate the objectives of the study, we employ the fully modified ordinary least square (FMOLS) and dynamic ordinary least squares estimators (DOLS) to draw the study findings. However, the estimated results show a negative association of land use with food security and supply. Likewise, energy transition, gross domestic product, and agricultural value added (AVA) contribute to the food security supply. In contrast, urbanization's negative but insignificant contribution to the food supply in selected economies exists. Besides, another core objective of the study is to investigate the moderate role of the energy transition on the gross domestic product, agriculture sector, and land use and find the significant contribution to the food supply. However, the current study also tries forecasting for the next 10 years and employs the impulse response function (IRF) and variance decomposition analysis (VDA). Congruently, this study uses the pairwise panel causality test and finds exciting outcomes. The COVID-19 crisis has posed challenges such as energy consumption and food security issues. On behalf of the results, the current study proposes imperative policies to investigate the desired level of food supply. The findings provide valuable insights for experts, policymakers, and officials to take practical measures for energy use and food security challenges.

Multi-objective non-linear solid transportation problem with fixed charge, budget constraints under uncertain environments

ABSTRACT Transportation-based models are widely used to solve real-life problems such as supply chain problems, inventory level problems, business models, management problems, etc. The parameters of these problems have been conventionally measured as deterministic. However, these parameters have vagueness due to the uncertainty in the data sets. Such uncertainty of the parameters is generally measured using randomness (probability theory) or fuzziness (fuzzy theory), with certain assumptions and limitations. Closed intervals interpretation is another concept to deal with the uncertainties of real-world issues in recent decades, avoiding the limitations in probability theory and fuzzy set theory. This study formulates a fixed-charged multi-objective non-linear solid transportation with parameters such as availability of items, conveyance capacity, transportation cost, requirement, and budget for destinations in the form of closed intervals, where objectives are minimization of total transportation cost and action of time under the restriction over budget. An efficient solution procedure is developed with the help of interval analysis based on the parametric perception of intervals. Initially, the objective functions are converted into a crisp function using multiple integrations, and as a result, the problem is converted into a deterministic multi-objective non-linear programming problem. In addition, a real-world numerical problem is considered for testing the developed solution process for greater comprehension and clarity.

FROM THE EDITOR

Short supply of quality paper affected the appearance of our Spring 2022 issue; many of the black-and-white images were muddied and titles in gray appear so faint as to be almost invisible. We’re hoping this issue will be more in keeping with previous production quality, but we may have to be patient. In an article published in March of this year in Publishers Weekly, Michael Seidlinger quotes one of the participants on a panel addressing this particular supply chain problem: “With mills [in the United States] converting their machines from manufacturing paper needed by publishers to producing much more lucrative packaging materials, printers and publishers are all having trouble getting the amount of paper they need. The paper shortage has been made more severe this year because most printers and paper merchants have run dry on their paper reserves. The expanded paper inventories of the past are no more” (“Examining Paper Shortages and Publishing Worker Unrest,” March 24, 2022). Another COVID victim . . .On a happier note, we received positive feedback for our new feature “Critical Reassessments,” and we look forward to future essays. We hope you enjoy Travis Montgomery’s reassessment of Jacobs’s Poe: Journalist and Critic (1969) in this issue. In 2023 Sami Atassi (Indiana University) will take on Daniel Hoffman’s Poe Poe Poe Poe Poe Poe Poe (1971) for the Spring issue, and Isaac Kolding (SUNY Buffalo) will assess Sidney Moss’s Poe’s Literary Battles (1963) for the Fall issue.Poe—again—will take center stage in 2023 with a conference sponsored by the Edgar Allan Poe Spanish Association. “‘Through the Veil of the Soul’: Poe and the Pleasures of Art” will be held in Albacete, Spain, October 4–6. The CFP was distributed on the PSA Listserv. We look forward to this conference organized by two of our PSA members—Margarita Rigal-Aragón and Fernando González Moreno. Hope to see many of you there!

When the chips are down [semiconductor chain - electronics

It hit the car manufacturers first and hard but then spread to other parts of industry during the worldwide pandemic. The shortages became so sharp that manufacturers were taking them out of other products for their own. I'm talking, of course, about semiconductors and the supply chain problems of the last few years. Chips are now a commodity, to be found in the humblest of items we use every day. That we take them for granted became clear only when we missed them. Now the shortages have eased, but what will the supply chain disruption mean for the electronics industry in the future? The author looks at what happened, why, whether it could have been avoided, and what's happening now. Is it the end of offshoring?

Aerospace and Defense the Financial Impact of Covid-19 on the Rolls-Royce Supply Chain

After the pandemic hit in 2020, the aerospace and defense industry was specifically impacted very harshly. Rolls-Royce was one of the main companies that had to go through major structural and logistical changes to cope with the changing economy. As one of the leaders of the aerospace and defense (A&D) industry, the main problem that Rolls-Royce was facing was the drastic reduction in demand for civil and commercial aircraft, which was one of Rolls-Royce’s core businesses. This led to supply chain problems, reduced profits, and eventually heavy losses. The effects of these problems caused great distress in the company. My specific role was twofold: to analyze their financial statements for the present and to provide risk management strategies for the future. For the former, I offer solutions on how they can minimize their losses and maximize their profits. Most of my research on this part was conducted by studying how companies performed under great financial distress in the past during black swan events, such as the housing crisis of 2008, the Great Recession, the dot-com bubble, and so forth. For the latter risk management objective, I created a personalized risk matrix for Rolls-Royce by identifying and ranking all their current and potential risks. Then I prioritized the risks that required more attention based on both qualitative and quantitative analyses of cost and performance impacts, and presented recommended solutions for these risks. Overall, I address six main issues and risks that Rolls-Royce should focus on and provide solutions to mitigate them.

Modeling and analysis of a sustainable supply chain with fairness concerns and green-sensitive consumer demand

PurposeWith the global spread of environmental education, environmental awareness is becoming increasingly important in daily life and economic activities. Sustainable development, as the most effective development approach to address global climate change, has gradually become a research hotspot in countries around the world. The authors combine sustainable development with supply chain management and incorporate into the study the objective issue of corporate fairness preferences in real society to explore the pricing and product greenness decision problem of a secondary sustainable supply chain consisting of a manufacturer producing green products and a retailer selling green products. In particular, the authors explore how supply chain decisions change when both the manufacturer and the retailer focus on fairness and how this fairness behavior affects pricing and product greenness decisions in sustainable supply chains.Design/methodology/approachThe authors consider that the manufacturers' greening efforts lead to expanded demand at the retail end. Upstream and downstream firms in the supply chain have preferences for the fairness of transactions. The impact of the fairness behavior of upstream and downstream firms in the supply chain on supply chain decisions is explored by building a Stackelberg game model.FindingsThe results of this study show that the fairness concern behavior of manufacturers and retailers in the supply chain has an impact on product greenness, product pricing and corporate profits.Originality/valueThis study on the fairness concern behavior of supply chain firms integrates behavioral economics and supply chain management. First, the authors consider the equilibrium problem of supply chain members in the centralized channel when there are no fairness preferences. Second, the decision problem of firms in the decentralized channel when fairness is considered and when fairness preferences are not considered is explored. The authors compare these three cases to derive the corresponding propositions. Finally, the authors verify the previous conclusions and draw other conclusions using arithmetic analysis.

Solving Urban Routing Problem in Supply Chain by Optimizing PSO Algorithm

Solving Urban Routing Problem in Supply Chain by Optimizing PSO Algorithm

Supplier selection framework to evade pseudo-resilience and to achieve sustainability in supply chains

PurposeDue to increasing uncertainty in the global business scenario, research on supply chain resilience is gaining significance. The outbreak of the COVID-19 pandemic has accelerated and magnified the issues already pertaining in the supply chain thereby increasing the vulnerabilities in the network. This study attempts to build the concept of pseudo-resilience in supplier selection and evaluation for supply chain sustainability.Design/methodology/approachA combination of multi-criteria decision-making methods AHP and R is adopted, and an integrated method called Combined AHP–R method is used to identify and include the property of pseudo-resilience into supplier selection processes.FindingsThe authors identified various factors contributing to pseudo-resilience considering supplier selection process and found the most important attribute. Using the combined AHP–R method, the suppliers were evaluated, considering the attributes contributing to the pseudo-resilience of supply chains and best supplier was selected.Originality/valueTo the best of our knowledge, this is the first study addressing a supplier selection problem for sustainable supply chains, considering pseudo-resilience. Also, this is the first study to apply the AHP–R method for supplier selection in the resilience or sustainability context.

Green investment in a sustainable supply chain: The role of blockchain and fairness

We study a green investment problem of a sustainable supply chain with one manufacturer who decides whether to implement blockchain and one retailer who has emotional fairness concerns. Although blockchain adoption is costly, it can raise customers’ green sensitivity level and exempt a firm from environmental taxes. A fair-minded retailer cares about disadvantageous inequity in addition to monetary payoffs. We compare the supply chain performance with and without blockchain, each in combination with and without emotional fairness concerns. We show that the manufacturer has the incentive to adopt blockchain if the operational cost is below a certain threshold, and this threshold increases in both tax rate and the blockchain-driven increment in customers’ green sensitivity. We find that fairness can encourage blockchain implementation if and only if the blockchain-driven increment in customers’ green sensitivity level is nominal. Moreover, blockchain adoption may weaken the positive impact of fairness on the supply chain performance such as the mitigation of double marginalization and consumer welfare improvement. We also find that blockchain can encourage green investment and benefit the retailer only if the blockchain-driven increment in customers’ green sensitivity level is relatively high; that is, an “all-win” situation for the supply chain can be achieved by blockchain adoption. Extended studies on consumption-based emission taxes and blockchain setup cost are also provided.

E-commerce supply chain network design using on-demand warehousing system under uncertainty

During the COVID-19 pandemic, e-commerce retailers have had trouble satisfying the growing demand because of limited warehouse capacity constraints. Fortunately, an on-demand warehousing system has emerged as a new alternative to mitigate warehouse capacity issues. In recent years, several studies have focused on the supply chain problem considering on-demand warehousing. However, there is no study that deals simultaneously with inherent uncertainties and the property of commitment, which is the main advantage of on-demand warehousing. To fill these research gaps, this paper presents an e-commerce supply chain network design problem considering an on-demand warehousing and decisions for commitment periods. We propose the two-stage stochastic programming model that captures the inherent uncertainties to formulate the presented problem. We solve the proposed model utilizing sample average approximation combined with the Benders decomposition algorithm. Of particular note, we develop a method to generate effective initial cuts for improving the convergence speed of the Benders decomposition algorithm. Computational results show that the developed method could find an effective feasible solution within a reasonable computational time for problems of practical size. Furthermore, we show the significant cost-saving effects, based on experiment results, that occur when an on-demand warehousing system is used for designing supply chain networks.

Blockchain Deployment in the Retail Supply Chain

The research aims to explore blockchain adoption for retail supply chain applications using two theoretical perspectives: supply chain capabilities and business value-added. Blockchain deployment in the retail supply chain helps in resolving some of the supply chain problems such as time delays, risks mitigation, information sharing, and product counterfeiting. In this study, various frameworks are conceptualized to understand, synthesize, and determine the value creation process. The research emphasizes that the benefits of blockchain deployment in the retail supply chain are broad-based and include enhanced trust and transparency, cost reduction, automation, increased processing speed, streamlined process, and disintermediation. The research also provides various illustrations to explain how retailers have successfully deployed blockchain technology in retail supply chains and improved their overall performance. Research also discusses the barriers to blockchain deployment in the retail supply chain and provides practical insights for smooth implementation.