Performance analysis and design of supply chains: a Petri net approach

In this paper, we investigated a dynamic modelling technique for analysing supply chain networks using generalised stochastic Petri nets (GSPNs). The customer order arrival process is assumed to be Poisson and the service processes at the various facilities of the supply chain are assumed to be exponential. Our model takes into account both the procurement process and delivery logistics that exist between any two members of the supply chain. We compare the performance of two production planning and control policies, the make-to-stock and the assemble-to-order systems in terms of total cost which is the sum of inventory carrying cost and cost incurred due to delayed deliveries. We formulate and solve the decoupling point location problem in supply chains as a total relevant cost (sum of inventory carrying cost and the delay costs) minimisation problem. We use the framework of integrated GSPN-queuing network modelling—with the GSPN at the higher level and a generalised queuing network at the lower level—to solve the decoupling point location problem.     

考虑公平关切的O2O模式下物流服务供应链定价策略博弈分析

针对两个物流服务提供商(FLSP)和单个物流服务集成商自营的线上物流平台(LSIO)组成的两层O2O模式下物流服务供应链,即考虑物流服务集成商(LSI)自营线上物流平台的情形,将公平关切引入到O2O模式下物流服务供应链的定价决策中,基于Stackelberg博弈模型,研究物流服务提供商(FLSP)的公平关切有限理性行为对物流服务供应链成员定价策略和效用的影响。研究结论表明:在仅考虑横向公平关切和考虑双向公平关切这两种情形下,后进入市场的物流服务提供商(FLSP2)都应控制自己的横向公平关切行为,否则会影响O2O模式下物流服务供应链的发展;在考虑双向公平关切的情形下,先进入市场的物流服务提供商(FLSP1)发现分配给自己的物流服务订单量减少后,FLSP1会对LSIO产生纵向不公平厌恶,而FLSP1的纵向公平关切程度达到一定水平后,物流服务集成商自营的线上物流平台(LSIO)应重视 FLSP1的纵向公平关切,避免物流服务提供商流失。     

Logistics cost sharing in supply chains involving a third-party logistics provider

In many cases, end customers are sensitive to a product’s logistics service level which is provided by a third-party logistics (3PL) provider, therefore, the continuous improvement of the logistics service is imperative and valuable. However, the problem is that improving the logistics service benefits all of them, but is costly to only the 3PL provider. The 3PL provider is not willing to do this. Sharing the logistics cost is one solution to this problem. This study investigates cost sharing in two kinds of supply chains, i.e., one manufacturer-one 3PL provider-one retailer supply chain and two manufacturers-one 3PL provider-one retailer supply chain. Two types of cost sharing mechanisms, i.e., decentralized cost sharing mechanisms and centralized cost sharing mechanisms, are explored. Decentralized cost sharing mechanisms are proposed as contracts that chain members separately decide their cost sharing portions to optimize their own profits, ignoring the collective impacts of their decisions on the channel as a whole. Centralized cost sharing mechanisms are in the situation that chain members negotiate their cost sharing portions so that their profits are the shares of the entire supply chain’s profit, implying that the supply chain is coordinated perfectly. This study aims to analyse how cost sharing mechanisms affect supply chain performance and under what conditions chain members are willing to engage in cost sharing mechanisms. Conditions necessary for cost sharing mechanisms to achieve win-win outcomes are identified.     

An analytic network process approach to the selection of logistics service providers for air cargo

Nowadays, enterprises typically outsource their logistics needs to logisticsagents, who have become vital partners in managing supply chains. The logisticsneeds in a supply chain consist of many different interrelated services, eachwith its own set of requirements and constraints. A logistics agent mightspecialize in the provision of a single logistics service or might provide arange of services. The selection of logistics agent(s) cannot be separated intoa series of stand-alone selections as the decisions are interrelated. Decisionmakers must assess the merits of individual activity-agent combinations, as wellas their interrelationships along the entire supply chain. Such an evaluation isnon-trivial, because both tangible and intangible elements are involved. In thisresearch, we model the selection problem using analytic network process, amultiattribute decision-making methodology suitable for assessing interdependentelements, both tangible and intangible. We examine the significance ofintegration and consolidation of shipments, the trade-offs between costs,benefits and risks within activities of the logistics process, and the differingroles of traditional freight forwarders and integrators.     

制造商主导下的CLSC物流策略和供应链稳定性

针对制造商主导的闭环供应链系统,考虑物流策略对系统的影响,运用博弈论理论,分析了物流外包和物流自营时制造商和零售商的定价策略、物流策略以及供应链稳定性.分析发现,无论是物流自营还是物流外包,随着补贴的增大,批发价格的单位变动率和单位再制造节约成本的单位变动率相等,但是方向相反.关于物流策略,无论补贴高低,只要fg1或者fg~21,则制造商和零售商在物流策略选择上始终一致,供应链具有长期稳定性.但若fg1fg~2,则制造商和零售商在物流选择上产生分歧,供应链具有不稳定性.     

基于供应链群体决策的物流服务集成商评估选择研究

物流服务的集成已经成为供应链之间进行竞争的主要优势来源之一,因此评估选择出使供应链上所有企业都感到满意的物流服务集成商至关重要.为此首先描述了物流服务集成的群体决策流程,随后建立了物流服务集成商的评估指标体系,从整条供应链的角度构建了基于层次分析法和多目标规划模型的群体决策方法,最后通过实例说明了利用该方法进行评估选择的具体过程.     

考虑即时采购价格的物流服务供应链优化

物流服务市场的不确定性会影响物流服务供应链的服务水平和收益。在考虑随机即时采购价格以及基础物流提供商在正常情况和应急情况下具有不同物流能力投资成本的情形下,引入期权机制研究不确定市场环境下物流服务供应链的优化决策,以提高物流服务供应链柔性和降低市场不确定性带来的风险。构建物流服务供应链的期权契约模型,采用Stackelberg博弈理论和优化算法分析和求得物流服务集成商的最优期权采购和即时采购策略,以及基础物流提供商的最优物流能力投资策略。结果表明即时采购价格将影响基础物流提供商和物流服务集成商的决策。最后通过数值分析研究即时采购价格的不确定程度对物流服务集成商和提供商的优化策略和利润的影响。     

Group and individual heterogeneity in a stochastic frontier model: Container terminal operators

Container ports are a major component of international trade and the global supply chain. Hence, the improvement of port efficiency can have a significant impact on the wider maritime economy. This paper deconstructs a representation in the existing literature that neglects the heterogeneity of individual and group-specific terminal operators. In its place, we present a hierarchical model to make a connection between efficiency and terminal operator group characteristics. The paper develops a stochastic frontier model that controls not only individual heterogeneity but also group-specific variations. The model decomposes the total stochastic derivation from the frontier into inefficiency, individual heterogeneity, group-specific variations, and noise components, with the estimation being performed using Markov chain Monte Carlo simulations. The validity of the model is tested with a panel of container terminal operator data from 1997-2004. Our findings show that terminal operator groups are important in promoting terminal efficiency at the global level, and that the operators with stevedore backgrounds show a higher efficiency than carriers.     

Facility location and supply chain management – A review

Facility location decisions play a critical role in the strategic design of supply chain networks. In this paper, a literature review of facility location models in the context of supply chain management is given. We identify basic features that such models must capture to support decision-making involved in strategic supply chain planning. In particular, the integration of location decisions with other decisions relevant to the design of a supply chain network is discussed. Furthermore, aspects related to the structure of the supply chain network, including those specific to reverse logistics, are also addressed. Significant contributions to the current state-of-the-art are surveyed taking into account numerous factors. Supply chain performance measures and optimization techniques are also reviewed. Applications of facility location models to supply chain network design ranging across various industries are presented. Finally, a list of issues requiring further research are highlighted.     

Coordinating a three-echelon fresh agricultural products supply chain considering freshness-keeping effort with asymmetric information

This paper studies the coordination problem of a three-echelon supply chain system consisting of one supplier, third-party logistics service providers (TPLSP) and one retailer that provides seasonal fresh agricultural products to customers. The market demand for the retailer is assumed to be influenced by the retail price, the product's freshness and other random variables. Both quantity and quality losses are viewed as endogenous variables of the freshness-keeping effort, which is decided by the TPLSP. Dynamic game models for both the decentralized decision mode and the centralized decision mode are developed, and asymmetric demand information is considered in the decentralized decision mode. The analysis shows that decentralized decision making could result in the distortion of the order quantity and selling price and could ultimately result in a loss of supply chain profit. The TPLSP is motivated to exaggerate the demand, which could seriously damage the supplier's interests. Based on an analysis of the major influencing factors in the supply chain system, a coordination contract based on cost and revenue sharing (RS) is designed for the two transaction processes in the three-echelon supply chain system. We illustrate the proposed models with a numerical study and conduct a sensitivity analysis of some of the key parameters in the models. It is proven that with the designed contract, the sales volume can be significantly expanded, all the supply chain members can benefit from Pareto improvement, and both the retailer and the TPLSP have no incentive to exaggerate the market demand.     

Supply chain network operations management of a blood banking system with cost and risk minimization

Blood service operations are a key component of the healthcare system all over the world and yet the modeling and the analysis of such systems from a complete supply chain network optimization perspective have been lacking due to their associated unique challenges. In this paper, we develop a generalized network optimization model for the complex supply chain of human blood, which is a life-saving, perishable product. In particular, we consider a regionalized blood banking system consisting of collection sites, testing and processing facilities, storage facilities, distribution centers, as well as points of demand, which, typically, include hospitals. Our multicriteria system-optimization approach on generalized networks with arc multipliers captures many of the critical issues associated with blood supply chains such as the determination of the optimal allocations, and the induced supply-side risk, as well as the induced cost of discarding the waste, while satisfying the uncertain demands as closely as possible. The framework that we present is also applicable, with appropriate modifications, to the optimization of other supply chains of perishable products.     

A multi-objective approach to supply chain visibility and risk

This paper investigates the twin effects of supply chain visibility (SCV) and supply chain risk (SCR) on supply chain performance. Operationally, SCV has been linked to the capability of sharing timely and accurate information on exogenous demand, quantity and location of inventory, transport related cost, and other logistics activities throughout an entire supply chain. Similarly, SCR can be viewed as the likelihood that an adverse event has occurred during a certain epoch within a supply chain and the associated consequences of that event which affects supply chain performance. Given the multi-faceted attributes of the decision making process which involves many stages, objectives, and stakeholders, it beckons research into this aspect of the supply chain to utilize a fuzzy multi-objective decision making approach to model SCV and SCR from an operational perspective. Hence, our model incorporates the objectives of SCV maximization, SCR minimization, and cost minimization under the constraints of budget, customer demand, production capacity, and supply availability. A numerical example is used to demonstrate the applicability of the model. Our results suggest that decision makers tend to mitigate SCR first then enhance SCV.     

Optimal number and location of storage hubs and biogas production reactors in farmlands with allocation of multiple feedstocks

This paper focuses on the problem for designing a logistics system for bio-methane gas (BMG) production. In practice, farm residues such as crop residue, wood residue, and livestock manure are used in reactors as reactants to generate BMG. A multi-residue, multi-hub, multi-reactor location-allocation model is developed to design the logistics of BMG production system. Both the hubs’ and reactors’ locations, and the residue's distribution plan are investigated to minimize the total construction and logistical cost. The costs of construction, transportation, feedstocks and labor are taken into consideration to reflect the lifecycle cost of the entire undertaking. In this paper, a mixed-integer nonlinear problem is proposed to simulate a BMG production supply chain. In addition to the optimal solution methods, a search-based heuristic was also proposed to determine the locations of hubs and reactors for large instances and along with a proper allocation of residues that are transported from the farms to the hubs to the reactors. Several numerical examples are tested to evaluate the performance of the heuristic as well.     

Demand uncertainty in construction supply chains: a discrete event simulation study

The delivery of construction projects is typically an assembly operation involving a high number of subassemblies and materials brought on site by the supply chain. However, although supply chain management in construction has attracted significant attention, paradoxically little focus has been placed on construction supply networks and operations. This paper places emphasis on supply chain operations by looking at the logistics function of construction material suppliers. Specifically, the paper examines the impact of demand uncertainty on supply chain performance in order to assess the capacity of material distribution companies to provide a timely and cost-efficient service to the construction industry. The study adopts a discrete event simulation approach to assess the impact of demand fluctuations on two crucial logistics performance measures; lead time and cost efficiency. The results show that lead times are particularly sensitive to fluctuations under conditions of low demand. The findings also reveal that, although transport is a significant cost element for lower demand levels, higher inventory costs result in a negative exponential relationship between increasing demand and cost efficiency.     

公平关切下物流服务供应链质量缺陷承诺策略研究

考虑物流服务供应链中成员的公平关切行为,以Nash讨价还价均衡解作为公平收益参照点,构建Nash讨价还价公平关切下物流服务供应链质量缺陷承诺策略模型,分析和研究公平关切对最优策略、利润和效用的影响。研究结果表明,物流服务质量缺陷承诺水平随着物流服务集成商公平关切系数的增加而减少,却随着物流服务提供商公平关切系数的增加而增加;物流服务订购量随着物流服务集成商公平关切系数的增加而减少,也随着物流服务提供商公平关切系数的增加而减少;当物流服务提供商的公平关切系数增加时,物流服务供应链中各成员的利润和效用以及整体利润和效用都会不断减少;但当物流服务提供商的公平关切程度一定而物流服务集成商的公平关切系数增加时,物流服务供应链中各成员的利润和效用以及整体利润和效用不断提高。     

An assembly-type supply chain system controlled by kanbans under a just-in-time delivery policy

This research studies the assembly-type supply chain system controlled by kanban mechanism. First, a supply chain system is modeled as a mixed-integer nonlinear programming (MINLP) problem. A composite formulation of the assembly-type supply chain system is developed by appropriately aggregating the individual branch models as a whole system. The batch size, the number of batches, and the total quantity over one period in the mainline and each branch line are determined. The small size MINLP problems are solved optimally by a branch-and-bound method. For the large size MINLP problems, a heuristic is developed which divides the ATSCS into several small size problems, and then conquers them individually. Next, the kanban operation between two adjacent plants is developed to schedule the loading and unloading, and transportation. Coupled with plant-wide efforts for cost control and management commitment, a logistics system is built for controlling the production as well as the supply chain system, which results in minimizing the total cost of the supply chain system. Numerical examples are presented to illustrate the two heuristic procedures and a better solution is obtained for the ATSCS problem.     

供应链物流合作伙伴选择的多层次灰色评价方法

为了获得高效的供应链体系，物流业务外包已成为制造企业增加竞争力最重要和最有效的战略手段之一。本文研究了物流外包中的物流合作伙伴选择问题。基于制造商与物流供应商长期合作的伙伴关系，从成本、服务质量、合作稳定性以及综合实力四个方面设计了物流合作伙伴评价指标体系。针对主观的评价指标体系，建立了灰色评价与层次分析法相结合的多层次灰色评价模型，并进行了算例研究。     

网络传媒业供应链质量控制策略与组织模式选择

网络传媒供应链由内容制作商提供有价值的信息产品(如娱乐、资讯等)并通过网站提供给消费者.产品质量控制对网络传媒供应链至关重要.首先利用博弈论的方法分析内容制作商和网站分别独立决策时的策略,纳什均衡揭示双方的"搭便车"动机使供应链整体利润无法达到最优.然后利用最优化的方法分析他们在垂直整合模式下的策略,发现协调决策可以提高整体利润.最后考虑垂直整合模式的新增成本,分析需求质量弹性、利润分配均匀性和质量控制成本等因素对供应链是否采取垂直整合模式的影响.帮助理解网络媒体产业的质量控制策略和供应链组织模式.     

A single-stage supply chain system controlled by kanban under just-in-time philosophy

The production system using kanban was pioneered by Toyota Motor Company in Japan and subsequently it was adopted by numerous other Japanese and US companies for applying the just-in-time manufacturing principles. This research studies a single-stage supply chain system that is controlled by kanban mechanism. The supply chain system is modelled as a mixed-integer nonlinear programming (MINLP) problem. It is solved optimally by branch-and-bound method to determine the number of kanbans, batch size, number of batches, and the total quantity over one period. Meanwhile, the kanban operation between two adjacent plants is worked out considering the factors of loading and unloading time, and transport time. Coupled with plant-wide efforts for cost control and management commitment to enhance other measures of performance, a logistics system for controlling the production as well as the supply chain system is developed, which results in minimizing the total cost of the supply chain system. The results show that the improvements in reduction of inventory, wasted labour, and customer service in a supply chain are accomplished through the kanban mechanism.     

基于客户信用度的物流配送车辆路径问题研究

针对当前城市物流配送过程中普遍存在的客户中途取消订单、无故退换货等交易违约问题,引入客户信用度的测度方法。根据客户历史交易违约数据计算客户信用值,并转化求解客户信用度,构建了包含车辆配送成本、租赁成本以及违反时间窗惩罚成本的配送路径优化模型。设计了一种遗传(GA)-禁忌搜索(TS)混合算法进行模型求解,在算法过程中应用精英保留策略进行循环迭代寻优。结合重庆某外卖物流配送网络的实例数据,验证了模型和算法的有效性和可行性。实验结果给出了不同服务策略下的物流配送调度方案,并进行了基于客户信用度的客户配送服务序列调整比较和敏感度分析。研究表明客户信用等级的合理划分可以有效降低物流配送成本和提高客户服务水平。