Temporary Hubs for the Global Vehicle Supply Chain in Humanitarian Operations

We model the global vehicle supply chain of an International Humanitarian Organization (IHO) with a dynamic hub location model across monthly periods. We use actual vehicle data from the International Federation of the Red Cross to feed our model and provide insights into IHO secondary support demand. We find that secondary support demand for items such as vehicles is different from primary beneficiary demand for items such as water and food. When considering disaster response and development program demand simultaneously (disaster cycle management), our results illustrate that keeping a lean centralized hub configuration with an option for temporary hubs in mega disaster locations can reduce overall supply chain costs over a long time horizon. We also show that it is possible to structure a supply chain to take operational advantage of earmarked funding. This research lays the groundwork for using optimization models to analyze disaster cycle management.     

多产品救援物资的储备决策:一个扩展的Newsvendor模型

储备一定数量的救援物资用于应对可能的灾害事件对于改善救援工作的绩效有着重要的意义。在考虑救援组织机构面对多种可能的灾害事件的基础上，本文利用一个二阶段交付过程模型来刻画灾害事件发生后救援物资的交付。该模型明确救灾组织在灾害事件发生后首先交付储备物资，如果需求短缺则再综合利用社会捐赠物资和应急采购满足剩余需求。以期望总成本最小化为目标，在需求全部被满足的前提下，本文建立了多产品救援物资的储备决策模型，并给出了其最优解的隐函数形式。进一步，考虑救灾物资储备存在预算限制，研究了具有预算限制的多产品救援物资储备决策模型，并设计了一种二分法的求解算法。数值算例的计算结果则对所建立模型及算法进行了检验。     

Editorial for special issue on: humanitarian operations management

Abstract

Over the past decades, there has been increasing interest in studying humanitarian operations management. The mismatch between global humanitarian needs and the resources available, together with chronic vulnerability in many parts of the world, continues to have a direct bearing on the lives of millions of people in need of assistance. It also means that donors have to re-double their efforts to respond to disasters in a more efficient and effective manner. International humanitarian organizations (IHOs) often deal with a mix of disaster response and development programmes simultaneously. This operational mix entails disaster cycle management challenges such as project and programme planning of multi-objective global logistics, balancing earmarked donations for disaster response with budget needs for development programmes, and determining the push-pull boundaries in the supply chain, particularly with the increase in cash transfer programmes. The main purpose of this special issue is to report on research in humanitarian operations management. This special issue attempts to explore and examine the above topical issues at strategic, operational and technical levels.     

An option contract pricing model of relief material supply chain

Relief material management which aims to reduce the impact of disaster and maintain social stability is of great importance for nonprofit organization (NPO) such as government, department of civil affair or Red Cross. However, the research of efficiency and performance on this field has long been ignored. In order to improve the efficiency and performance of the relief material management, we apply the supply chain management method into this field. Considering the relief material management system as a supply chain with one buyer and one supplier, we introduce the option contract mechanism into relief material supply chain management. With reasonable assumptions, we design an option contract with two delivery steps, and build an option pricing model with binominal lattice to estimate the different values of the same option contract for both members of supply chain. Furthermore, we analyze the impacts of the different parameters (such as the ratio of inventory, subjective probability of disaster, etc.), on the supply chain and its members in detail. The numerical example presented at last demonstrates that, with two delivery steps, there is a feasible price range of option contract which makes both members of relief material supply chain profitable and willing to conduct the transaction with option contract.     

How to Integrate Labor Disruption into an Economic Impact Evaluation Model for Postdisaster Recovery Periods

Evaluating the economic impacts caused by capital destruction is an effective method for disaster management and prevention, but the magnitude of the economic impact of labor disruption on an economic system remains unclear. This article emphasizes the importance of considering labor disruption when evaluating the economic impact of natural disasters. Based on the principle of disasters and resilience theory, our model integrates nonlinear recovery of labor losses and the demand of labor from outside the disaster area into the dynamic evaluation of the economic impact in the postdisaster recovery period. We exemplify this through a case study: the flood disaster that occurred in Wuhan city, China, on July 6, 2016 (the “7.6 Wuhan flood disaster”). The results indicate that (i) the indirect economic impacts of the “7.6 Wuhan flood disaster” will underestimate 15.12% if we do not consider labor disruption; (ii) the economic impact in secondary industry caused by insufficient labor forces accounts for 42.27% of its total impact, while that in the tertiary industry is 36.29%, which can cause enormous losses if both industries suffer shocks; and (iii) the agricultural sector of Wuhan city experiences an increase in output demand of 0.07% that is created by the introduction of 50,000 short‐term laborers from outside the disaster area to meet the postdisaster reconstruction need. These results provide evidence for the important role of labor disruption and prove that it is a nonnegligible component of postdisaster economic recovery and postdisaster reduction.     

基于手机定位数据的突发事件下道路修复和物资配送集成优化研究

应急道路的修复是突发事件发生后有效开展物资配送的前提,而道路修复和物资配送二者集成研究极大地提高整个应急救援效率。但是由于灾害的突发性和不确定性,决策者很难立即获取充分的灾情信息,尤其是灾民分布情况、位置、灾害影响和物资需求等信息。传统的获取灾情信息的方法通常是通过救援人员的现场报导和调查,卫星图像等,阻碍了救援活动的迅速开展,效率低下。手机等移动设备的普及和广泛应用,使得手机定位数据为灾害情况下的应急救援提供了更加快捷的信息获取手段,大大提高了应急救援的效率。本文基于手机定位数据,同时结合道路修复和物资配送二者的相互关系,建立了混合整数线性规划模型,通过手机定位数据获取灾民分布情况、位置、灾害影响和物资需求等信息,实现精准道路修复和物资配送的决策,并设计了相应的启发式求解算法。最后通过算例仿真验证了模型和算法的有效性,同时将手机定位数据下的救援结果与缺少手机定位数据的常规救援结果进行比较分析,验证了文章所提出的手机定位数据的应用在应急救援方面的优势。     

Stochastic Optimization for Natural Disaster Asset Prepositioning

A key strategic issue in pre‐disaster planning for humanitarian logistics is the pre‐establishment of adequate capacity and resources that enable efficient relief operations. This paper develops a two‐stage stochastic optimization model to guide the allocation of budget to acquire and position relief assets, decisions that typically need to be made well in advance before a disaster strikes. The optimization focuses on minimizing the expected number of casualties, so our model includes first‐stage decisions to represent the expansion of resources such as warehouses, medical facilities with personnel, ramp spaces, and shelters. Second‐stage decisions concern the logistics of the problem, where allocated resources and contracted transportation assets are deployed to rescue critical population (in need of emergency evacuation), deliver required commodities to stay‐back population, and transport the transfer population displaced by the disaster. Because of the uncertainty of the event's location and severity, these and other parameters are represented as scenarios. Computational results on notional test cases provide guidance on budget allocation and prove the potential benefit of using stochastic optimization.     

考虑供应风险的多源应急物资采购双层规划模型

自然灾害频繁发生,事故灾难不断涌现,公共卫生事件猝不及防,社会安全风险交织叠加,给人们的生产和生活带来了巨大的风险和不确定性。在突发事件背景下,考虑应急物资供应中的各类风险,激励多源应急物资的稳定供给,受到党和政府高度重视。应急物资供应有哪些风险,如何规避这些风险,针对多种渠道的采购,如何优化采购结构。这些问题是本论文关注的重点。本文以政府、制造型企业、受灾地区民众为决策主体的三级供应链为基础,构建了上层以整个供应链系统收益最大化为目标函数、下层以供应风险最小化为目标函数的双层规划模型,对不同情景下物资采购订单的分配进行研究。在此基础上,本文以某市洪涝灾害为例进行分析,证明了模型的可行性,并探究了供应风险变化对物资采购订单分配、以及整个供应链系统收益的影响,以期为政府应急物资采购决策提供参考性建议。     

Complexity and Self‐Sustainment in Disaster Response Supply Chains

Governmental organizations play a major role in disaster relief operations. Supply chains set up to respond to disasters differ dramatically in many dimensions that affect the cost of relief efforts. One factor that has been described recently is self‐sustainment, which occurs when supplies consumed by intermediate stages of a supply chain must be provided via the chain itself because they are not locally available. This article applies the concept of self‐sustainment to response supply chains. A mathematical model of a self‐sustaining response supply chain is developed. Analysis of this model yields insights about the relationships and interactions among self‐sustainment, speed of disaster onset, dispersion of impact, and the cost of the relief efforts.     

Managing Logistics in Regional Banknote Supply Chain Under Security Concerns

We study the logistics problem faced by Regional Branches (RBs) of a central bank in managing the currency supply under security concerns. While making banknote supply decisions to Sub‐Branches (SBs), the management of RB must achieve two goals simultaneously: (i) guarantee that each SB has sufficient inventories of all denominations of banknotes to satisfy the demands from all commercial banks within its service area, and (ii) control the annual spending on this banknote supply operation. Due to security concerns, the following methods are implemented in the process of transporting banknotes: (i) the capacity of a cash truck is limited by the total face value (instead of the physical space) of banknotes, and (ii) empty decoy trucks are deployed along with the trucks filled with banknotes. After deriving a polynomial‐time strategy to guarantee an optimal solution for the special Bin‐Packing Problem faced in this study, we provide an exact formulation for the RB's supply planning problem. We also propose several polynomial‐time algorithms for deriving either optimal or near‐optimal solutions for the problem under different settings. Using the weekly demand data obtained from the central bank, we verify the performance of our algorithms, and analyze the impacts of changes in these features and in the fleet capacity on the total cost incurred by an RB under various scenarios.     

Humanitarian Funding in a Multi‐Donor Market with Donation Uncertainty

This study analyzes the trade‐off between funding strategies and operational performance in humanitarian operations. If a Humanitarian Organization (HO) offers donors the option of earmarking their donations, HO should expect an increase in total donations. However, earmarking creates constraints in resource allocation that negatively affect HO's operational performance. We study this trade‐off from the perspective of a single HO that maximizes its expected utility as a function of total donations and operational performance. HO implements disaster response and development programs and it operates in a multi‐donor market with donation uncertainty. Using a model inspired by Scarf's minimax approach and the newsvendor framework, we analyze the strategic interaction between HO and its donors. The numerical section is based on real data from 15 disasters during the period 2012–2013. We find that poor operational performance has a larger effect on HO's utility function when donors are more uncertain about HO's expected needs for disaster response. Interestingly, increasing the public awareness of development programs helps HO to get more non‐earmarked donations for disaster response. Increasing non‐earmarked donations improves HO's operational efficiency, which mitigates the impact of donation uncertainty on HO's utility function.     

基于双层规划的反恐应急设施选址模型及算法

恐怖袭击常以人流密集地区的平民作为袭击目标，并存在突发性和随机性等特点，极易造成严重的袭击后果。通过反恐应急设施的合理布局可以缩短救援人员和物资的到达时间，从而减轻袭击后果。首先，对反恐应急设施选址问题进行描述，并将其构造为一类离散双层规划模型。其中，上层规划是关于政府选址的0-1规划问题，下层规划则是关于恐怖分子袭击目标选择的0-1规划问题。其次，结合模型和问题的特征设计算法，利用分支定界算法实现上层选址变量的隐枚举，同时通过下层问题的求解来确定上下界并判断是否满足分枝或剪枝的条件。最后，结合南疆地区的交通拓扑网络进行算例分析，结果证明有效的选址方案可以大大降低袭击损失。     

Two-sided assembly line balancing: A genetic algorithm approach

A two-sided assembly line balancing problem is typically found in plants producing large-sized high-volume products, e.g. buses and trucks. The features specific to the assembly line are described in this paper, which are associated with those of: (i) two-sided assembly lines; (ii) positional constraints; and (iii) balancing at the operational time. There exists a large amount of literature in the area of line balancing, whereby it has mostly dealt with one-sided assembly lines. A new genetic algorithm is developed to solve the problem, and its applicability and extensibility are discussed. A genetic encoding and decoding scheme, and genetic operators suitable for the problem are devised. This is particularly emphasized using problem-specific information to enhance the performance of the genetic algorithm (GA). The proposed GA has a strength that it is flexible in solving various types of assembly line balancing problems. An experiment is carried out to verify the performance of the GA, and the results are reported.     

交叉销售下基于支持向量聚类的数据驱动多产品库存鲁棒优化模型

针对单周期环境下考虑交叉销售的多产品库存决策问题,在市场需求不确定条件下,建立了带有预算约束的交叉销售多产品库存鲁棒优化模型。针对不确定市场需求,采用支持向量聚类(SVC)方法构建了满足一定置信水平的数据驱动不确定集。进一步,运用拉格朗日对偶方法将所建模型等价转化为易于求解的线性规划问题。最后,通过数值计算对比分析了SVC不确定集下及传统不确定集下的零售商利润绩效,并评估了SVC数据驱动鲁棒优化方法导致的绩效损失,进而分析了预算及交叉销售系数对零售商利润绩效的影响。结果表明,SVC数据驱动鲁棒优化方法具有良好的鲁棒性,能够有效抑制需求不确定性对从事多产品销售的零售商利润绩效的影响。特别地,需求分布信息的缺失虽然会给零售商带来一定的绩效损失,但损失值很小,表明文中提出的基于SVC的数据驱动鲁棒优化方法可以为管理者在需求不确定性环境下制定库存策略提供有效决策借鉴。     

竞争中的参考价格效应及承诺

消费者的社会感知会影响其对产品和品牌的评价。当消费者进行购买选择时,经常会受到参考价格效应的影响。而广告和价格不仅是企业经常要考虑的重要决策,还会对参考价格产生重要影响。为此,一个值得研究的的问题是：在考虑参考价格效应的情况下,企业该怎样确定其动态广告和价格策略？
为了研究该问题,本文构建了一个广告和价格的动态模型,来研究一个双寡头市场环境下两个寡头企业的价格和广告决策,并以此分析参考价格效应的作用。具体而言,我们假定企业可以采用广告承诺和价格承诺中的一种,其中前者承诺其在一段时间内的广告投入量恒定不变,而后者确保价格不变。两种策略不仅会影响消费者的购买决策,也会影响竞争对手的选择。在上述假定下,我们探讨了两个寡头企业在都采用广告承诺、都采用价格承诺及一个企业采用广告承诺而另一个企业采用价格承诺等三种不同情形下的最优广告和价格决策,并以此分析了三种情形下参考价格效应对最优的广告投入及定价策略的影响。最后,通过数值分析,探讨了不同情形下企业的最优策略选择。     

The Impact of Wireless Technology on Loading Trucks at an Auto Parts Distribution Center

An intervention was introduced for truck loaders that used wireless vehicle mount computers that included auditory, visual feedback, and immediate data delivery. The implementation reliably reduced pallets from being loaded out of sequence for all outbound trucks in multistop routes. The role of the organizational behavior management (OBM) practitioner in designing work procedure changes using technical solutions, requiring a minimum of training, to accelerate key operational processes was examined.     

Roy’s Safety‐First Portfolio Principle in Financial Risk Management of Disastrous Events

Roy pioneers the concept and practice of risk management of disastrous events via his safety‐first principle for portfolio selection. More specifically, his safety‐first principle advocates an optimal portfolio strategy generated from minimizing the disaster probability, while subject to the budget constraint and the mean constraint that the expected final wealth is not less than a preselected disaster level. This article studies the dynamic safety‐first principle in continuous time and its application in asset and liability management. We reveal that the distortion resulting from dropping the mean constraint, as a common practice to approximate the original Roy’s setting, either leads to a trivial case or changes the problem nature completely to a target‐reaching problem, which produces a highly leveraged trading strategy. Recognizing the ill‐posed nature of the corresponding Lagrangian method when retaining the mean constraint, we invoke a wisdom observed from a limited funding‐level regulation of pension funds and modify the original safety‐first formulation accordingly by imposing an upper bound on the funding level. This model revision enables us to solve completely the safety‐first asset‐liability problem by a martingale approach and to derive an optimal policy that follows faithfully the spirit of the safety‐first principle and demonstrates a prominent nature of fighting for the best and preventing disaster from happening.     

多受灾点应急物资动态多阶段分配模型研究

针对传统的单阶段物资分配模型可能导致应急物资分配的局部冗余或短缺、高成本、系统无法达到全局最优等现实情况,通过在指数效用函数中引入灾民物资需求的比例短缺测度公平,以物资短缺的延迟损失最小化与物资分配的总成本最小化为目标构建考虑多集散点、多配送中心和多受灾点的三级配送网络的应急物资动态多阶段分配模型,设计了目标转化与线性近似相结合的模型求解方法,并通过算例对所提出模型的有效性和可行性进行了验证。结果表明：所提出的多阶段模型能够兼顾物资分配的效率与公平,最大程度地降低物资短缺的延迟损失以及物资分配的总成本;运用灾民物资需求的比例短缺量化公平,避免了由于各受灾点的需求量差异而对公平分配产生的影响,可以使各受灾点即使在应急救援初期物资有限、中期物资持续供不应求等情况下,仍然能够在每阶段获得一定比率的所需物资,进而避免较大的物资短缺损失,确保多受灾点之间多阶段应急物资分配的公平性,更符合灾害救援实际,可为现实大规模灾害应急救援物资多阶段分配提供决策支持。     

考虑异质性行为的灾后应急物资动态调度优化

在以人道主义为本的应急救援活动中，不可忽视被救灾民和施救决策者们异质性行为的影响。一方面，将各灾民因救援物资需求未被及时满足而呈现的差异化心理痛苦度量成经济损失，并纳入应急救援调度的社会成本这一决策目标中；另一方面，在灾后物资调度决策中，关注具有异质性偏好的各应急决策者所展现出的不同救援态度。结合面向联合机会约束规划的动态供需平衡限制，最终构建一个考虑灾民和决策者们异质性行为的多阶段灾后救援物资分配和应急路径优化模型。采用2008年汶川地震为案例背景，应用遗传算法对模型求解和参数分析，将仿真结果与不考虑异质性行为的传统救援调度方案进行比较，得出一些结论为构建高效的应急救援体系提供有益参考。     

Coordinating replenishments in a supply chain with quality control considerations

We study the impact of coordinated replenishment, a popular supply chain initiative, on a quality control system. We use the (Q, S) policy to manage a two-item inventory control system. If the items are jointly replenished, the number ordered for each item varies from lot to lot. As the number varies, the sampling plan will also be changed. Companies have to determine sampling plans to minimize quality cost when the order is mixed with several items and the number of each item varies from order to order. Management's primary concern is to determine the optimal sampling sizes and acceptance numbers for all items in an order.