Pre-positioning hurricane supplies in a commercial supply chain

Inventory control for retailers situated in the projected path of an observed hurricane or tropical storm can be challenging due to the inherent uncertainties associated with storm forecasts and demand requirements. In many cases, retailers react to pre- and post-storm demand surge by ordering emergency supplies from manufacturers posthumously. This wait-and-see approach often leads to stockout of the critical supplies and equipment used to support post-storm disaster relief operations, which compromises the performance of emergency response efforts and proliferates lost sales in the commercial supply chain. This paper proposes a proactive approach to managing disaster relief inventories from the perspective of a single manufacturing facility, where emergency supplies are pre-positioned throughout a network of geographically dispersed retailers in anticipation of an observed storm's landfall. Once the requirements of a specific disaster scenario are observed, supplies are then transshipped among retailers, with possible direct shipments from the manufacturer, to satisfy any unfulfilled demands. The manufacturer's pre-positioning problem is formulated as a two-stage stochastic programming model which is illustrated via a case study comprised of real-world hurricane scenarios. Our findings indicate that the expected performance of the proposed pre-positioning strategy over a variety of hurricane scenarios is more effective than the wait-and-see approach; currently used in practice.     

库存成本约束下的供应链协调研究

在随机需求下,库存协调研究的核心是达到供应链整体成本的最小化,文中在考虑库存持有成本和缺货惩罚成本的情况下构建了基于供应商和零售商的基准库存水平的成本函数,在此基础上分别比较了集中决策和分散博弈下的纳什均衡最优情况。然后给出一个线性转移支付契约来达到整个供应链的协调,实现了库存成本在销售层面的任意分配。     

Planning the delivery of relief supplies upon the occurrence of a natural disaster while considering the assembly process of the relief kits

Models for the distribution of relief supplies often assume immediate availability of relief items upon the occurrence of a natural disaster. However, such an assumption does not always apply in realistic settings. In some cases, at least it is necessary to assemble relief items into kits before distributing them among the affected population. This paper presents a rolling horizon methodology that considers dynamic parameters such as demand, capacities and demand priorities for the problem of distributing relief supplies after the occurrence of a natural disaster by including such assembling activities before the delivery.     

A model for planning locations of temporary distribution facilities for emergency response

We propose a network flow model for dynamic selection of temporary distribution facilities and allocation of resources for emergency response planning. The model analyzes the transfer of excess resources between temporary facilities operating in different time periods in order to reduce deprivation. Numerical analysis shows that the location of temporary facilities is determined by the demand and supply points. This work contributes to the emergency response planning that requires a quick response for the supply of relief materials immediately after a disaster hits a particular area.     

Dynamic inventory decisions for humanitarian aid materials considering budget limitations

In case of disaster, providing relief supplies to the affected people has vital importance. Governmental or non-governmental organizations (NGOs) prepare for disasters by purchasing and stockpiling these aid materials in appropriate quantities. They operate under a limited budget and this budget can either be used before the disaster for stocking decisions under uncertainty or it can be used after the disaster to satisfy the required demand at a higher cost when the uncertainty is resolved. If all the budget is used before the disaster, and if there is no disaster in a long term, there will be a high holding cost. On the other hand, if all the budget is reserved for use after the disaster, meeting the demand will be more costly or the demand may not be met within a certain period of time. Thus, NGOs need to decide how to allocate the budget for pre and post-disaster usage. In this system, the budget of NGOs may also change over time through donations or other incomes. In this point of view, NGOs need to make dynamic stock and budget allocation decisions, under the available budget at hand. In our study, we analyze the dynamic stocking decisions of NGOs using stochastic dynamic programming formulations under budget constraints. We develop infinite horizon stochastic dynamic programming models with and without budget considerations, and compare the results of these models via numerical analysis. Detailed numerical studies and results of the sensitivity analysis show the significance of budget considerations in inventory decisions and the effects of different parameters on the system results.     

Debris removal during disaster response: A case for Turkey

Debris occurs from the ruin and wreckage of structures during a disaster. Proper removal of debris is of great importance because it blocks roads and prohibits emergency aid teams from accessing disaster-affected regions. Poor disaster management, lack of efficiency and delays in debris removal cause disruptions in providing shelter, nutrition, healthcare and communication services to disaster victims, and more importantly, result in loss of lives. Due to the importance of systematic and efficient debris removal from the perspectives of improving disaster victims quality of life and allowing the transportation of emergency relief materials, the focus of this study is on providing emergency relief supplies to disaster-affected regions as soon as possible by unblocking roads through removing the accumulated debris. We develop a mathematical model for the problem that requires long CPU times for large instances. Since it is crucial to act quickly in an emergency case, we also propose a heuristic methodology that solves instances with an average gap of 1% and optimum ratio of 80.83%.     

论自然灾害应急物流管理体系的构建

中国是世界上受自然灾害影响非常严重的国家之一,应急物流是救灾应急管理中必不可少的内容和环节.自然灾害应急物流管理体系,是为了实现在突发自然灾害环境下对应急物资、人员、信息和财产等进行有效组织和保障而建立的综合管理体系.文章根据我国目前突发自然灾害应急物流的实际情况,以自然灾害应急物流管理体系为研究对象,对自然灾害背景下应急物流管理体系的构建进行了研究,同时还提出了促进应急物流管理体系建设的一些建议.     

A two-period newsvendor model for prepositioning with a post-disaster replenishment using Bayesian demand update

Humanitarian aid agencies usually resort to inventory prepositioning to mitigate the impact of disasters by sending emergency supplies to the affected area as quickly as possible. However, a lack of replenishment opportunity after a disaster can greatly hamper the effectiveness of the relief operation due to uncertainty in demand. In this paper, a prepositioning problem is formulated as a two-period newsvendor model where the response phase is divided into two periods. The model acknowledges the demand to be uncertain even after the disaster and utilises the Bayesian approach to revise the demand of the second period. Based on the revised demand, an order is placed at the beginning of the second period to be replenished instantaneously. A two-stage solution methodology is proposed to find the prepositioning quantity and post-disaster replenishment quantity, which minimise the total expected costs of relief operations. A numerical example is presented to demonstrate the solution methodology, and sensitivity analysis is performed to examine the effect of model parameters. The results highlight the indifferent characteristics shown by the replenishment quantity with the variation in model parameters.     

A dynamic model for disaster response considering prioritized demand points

This paper addresses the problem of distributing relief supplies after the occurrence of a disaster. We develop a dynamic model to serve demand, while prioritizing the response, according to the level of urgency of demand points. Our model is thought to be applied during a planning horizon and it considers dynamic demand, capacity constraints and priorities. To evaluate the applicability of our model, we use a real case study of a flood occurred in Colombia. We also test the computational solvability of our model and we propose and test different solution methodologies for solving larger instances of our problem.     

供应链优化管理:关于量折扣研究的分类

供应链管理中的量折扣研究一直是研究的热点问题之一。国外学者研究的重点在于解决整体供应链的有效协调性问题,而其中量折扣定价策略研究是促进供应链协调运作的有效手段。这些研究的大致可分为三类:(1)给定需求条件下研究如何协调生产及库存决策;(2)从营销的角度研究供应链的协调;(3)将第一类研究和第二类研究相结结合,同时考虑市场营销和生产库存协调运作。而国内学者虽然引入了一些新方法,但仍处于从第一类研究向第二、三类研究的发展阶段。     

Sustainable humanitarian supply chain management – exploring new theory

Disaster response operations aim at helping as many victims as possible in the shortest time, with limited consideration of the socio-economic context. During the disaster rehabilitation phase, the perspective needs to broaden and comprehensively take into account the local environment. We propose a framework of sustainable humanitarian supply chain management (SCM) that facilitates such comprehensive performance. We conceptualise the framework by combining literature from the fields of sustainable and humanitarian SCM. We test the framework through an analytic induction process by means of multiple case studies of four relief organisations. Our framework suggests that supply chain design needs to be aligned not only to relief organisations’ enablers, but also to the population's long-term requirements as well as any socio-economic and governmental contingency factors. A good fit between these dimensions leads to sustainable performance. The framework provides an instrument for relief organisations to achieve sustainable performance in the disaster rehabilitation phase.     

基于反馈控制原理的应急物资分配动态决策过程分析

随着灾害应急物流系统快速响应机制的建立,应急物资分配在降低自然灾害的影响方面体现出重要作用。应急物资需求具有突发性和动态性等特征,资源的分配是一个动态的过程。基于此借鉴反馈控制原理构建应急物资分配决策模型,对灾害应急物流中的应急物资分配动态决策过程进行分析。     

大型地震应急物资需求预测方法研究

大型地震给社会造成了重大的人员伤亡和财产损失,灾后应急物资的及时供应对挽救生命至关重要,而应急物资需求预测是供应的前提。本文利用BP神经网络算法对灾后人员伤亡人数进行预测,然后结合库存管理知识估算灾区应急物资的需求量,以期为灾后应急物资的筹措和配送决策提供参考。最后,运用该方法对"5.12汶川地震"中的极重灾区北川县的应急物资需求进行了估算。     

A multi-stage stochastic programming approach for pre-positioning of relief supplies considering returns

A dynamic pre-positioning problem is proposed to efficiently respond to victims’ need for relief supplies under uncertain and dynamic demand in humanitarian relief. The problem is formulated as a multi-stage stochastic programming model that considers pre-positioning with the dynamic procurement and return decisions about relief supplies over a time horizon. To validate the advantages of dynamic pre-positioning, three additional pre-positioning strategies are presented: pre-positioning with one-time procurement and without returns, pre-positioning with one-time procurement and returns, and pre-positioning with dynamic procurement and without returns. Using data from real-world disasters in the United States in the Emergency Events Database, we present a numerical analysis to study the applicability of the proposed models. We develop a sample average approximation approach to solving the proposed model in large-scale cases. Our main contribution is that we integrate dynamic procurement and return strategies into pre-positioning to decrease both costs and shortage risks in uncertain and dynamic contexts. The results illustrate that dynamic pre-positioning outperforms the other three strategies in cost savings. It also indicates that a higher return price is particularly helpful for decreasing unmet demand. The proposed models can help relief agencies evaluate and choose the solutions that will have the greatest overall effectiveness in the context of different relief practices.     

突发性自然灾害应急物资管理研究

在整个应急管理的工作中,有一项最为基础的工作,那就是对应急物资的管理。若要想使灾区群众的生活得到安定和保障,保证整个救援工作得以顺利展开和进行,首先就要搞好应急物资的管理工作。     

Dynamic decision and coordination in a low-carbon supply chain considering the retailer's social preference

We establish dynamic game models in a low-carbon supply chain consisting of a single manufacturer and a single retailer with social preference. This study investigates the complex dynamic characteristics of pricing decision and carbon abatement strategy in the supply chain and focuses on the impact of the retailer's social preference on pricing decision, carbon emission abatement strategy, profits, supply chain coordination, and complexity of dynamic models. We find that adjustment parameters of pricing and carbon emission abatement should be maintained in a certain range; otherwise, the system will be unstable and even chaotic through period double bifurcation or wave shape chaos. A higher social preference of the retailer is always beneficial to carbon abatement and the manufacturer and helps maintain the stability of the supply chain system. However, the impact on the long-term profitability of the supply chain is related to the state of the system. Compared with the setting of a centralized decision, the optimal carbon abatement strategy and supply chain profit in a decentralized decision are always less than those in a centralized setting, regardless of whether the retailer has social preference. Therefore, a side-payment self-executing contract is designed to coordinate the supply chain and achieve Pareto improvement. The coordination mechanism proposed in this study not only leads to Pareto improvement but also increases the stability of the supply chain system. Finally, this study enlightens management in operating a low-carbon supply chain.     

我国城市自然灾害与应急管理体系研究

对我国城市面对的突发自然灾害形势和特点进行了分析,认为我国城市自然灾害风险高,具有灾害形势复杂、救灾工作难度大的特点,目前我国城市灾害应急体系建设具备法制、体制、预案、人才基础,但也存在法制不健全、机制不完善、灾害意识淡薄的问题,提出了完善体制机制、健全机构、提高承灾能力、增强居民应对能力的相关对策和建议。     

联合库存管理在石油企业中的应用研究

从供应链协同管理的角度,构建了石油企业备件联合库存管理模型,该模型分为供应商与物资总库的联合和物资总库与分公司的联合两部分,使原来的分散库存变为集中库存。并采用建立网络信息系统、供需协调管理机制和直达供应的策略达到联合库存管理的目的。     

Risk management in humanitarian supply chain based on FMEA and grey relational analysis

The COVID-19 pandemic has disrupted the humanitarian supply chain management (HSCM) necessary for delivering emergency items during the disaster. The combined effects of climate change and the pandemic uncover the vulnerabilities of humanitarian supply chain operations and highlight the importance of risk management. This study aimed to identify priority risk factors and proposed mitigating risk strategies of a local government that is at the forefront of relief operations. It used Grey Relational Analysis (GRA) method to validate the Failure Mode and Effect Analysis (FMEA) approach in identifying priority issues relating to the supply chain risks. This paper reveals that the results of FMEA and GRA are almost similar.     

US share prices and real supply and demand shocks

Demand and supply sources of output movement are distinguished and the effects of shocks on stock prices are analysed. The real economy has a more pronounced effect on the stock market than vice versa and the influence from the real economy to the stock market is less important than shocks that are peculiar to the market itself. Supply and demand shocks have a greater impact on stock prices than they do on real economy variables and the sensitivity of real stock prices to supply fluctuations has waned while the sensitivity of real stock prices to demand-driven output fluctuations has increased.