基于仿真的三级供应链成本优化

针对供应链这种非线性和复杂系统,为了优化供应链的总成本,提高供应链的整体竞争力,提出了一种基于仿真的优化方法。首先建立了一个三级协作供应链的系统动力学模型,供应链上的企业需要求解多个决策变量来降低供应链总成本。然后详细展示了将系统动力学模型转换为Matlab程序模型的过程,并在两个模型中使用了多组随机参数进行对比验证。最后设计了适当的遗传算法进行求解。结果表明,这种基于仿真的优化方法不仅能反映出供应链系统的动态特征,而且求解速度快、精度高,能有效解决供应链系统中的单目标或多目标规划问题。系统动力学模型结构相对固定,也不适合异构的交互环境,该方法给系统动力学模型提供了良好的补充。转换为Matlab程序模型后,可以进行深入的仿真研究,灵活设置目标函数和约束条件,详细分析系统的动态变化过程,还能为其它应用提供交互接口。     

基于BSC和SD仿真的供应链绩效评价

成本和服务水平是供应链绩效评价申具有悖反关系的指标.提出了基于平衡计分卡(BSC)和系统动力学(SD)仿真的供应链绩效评价方法,建立了供应链成本与服务水平的数学模型.利用BSC和战略图界定供应链结构及其边界,建立供应链系统模型;由供应链模型构建SD仿真流图和供应链绩效指标的SD方程;通过SD仿真和参数调整平衡成本与服务水平之间的关系,实现供应链绩效的优化.以生产一分销子系统为例,验证方法的有效性.     

基于自组织理论的供应链系统演化机制研究

基于供应链系统的复杂性特征及其自组织行为模式,利用组织动力学模型和仿真技术,对供应链系统的演化机制进行了分析.研究发现,供应链系统的演化与系统的流量、厂商的依赖度和外部环境因素有关;通过仿真研究发现,供应链系统在适当的环境下可以获得稳定态并且存在从稳态向非稳态的临界(流量)值.研究结果表明,供应链系统内厂商通过协同运作,可以达到和谐稳定的合作关系.     

基于CAS的供应链网络结构动态分析

介绍了复杂自适应系统理论(CAS)的基本含义、特征及其在进行仿真研究上的优势,分析了供应链网络系统就是一个CAS系统,建立了基于CAS的供应链网络进化仿真模型,并进行了仿真研究,通过对仿真结果的分析揭示了供应链网络系统动态变化的规律。     

基于联合库存的供应链系统动力学研究

采用联合库存管理为库存管理模式,运用系统动力学(Vensim5．0)软件建立了供应链动态仿真模型。通过仿真结果输出,从瓶颈、长鞭效应、成本等三方面对模型进行分析和优化;通过计算机仿真对系统未来行为进行的描述,形成了供应链管理策略的实验室。从而既保证了该系统在实际运行时的效果,又避免了系统策略实施可能带来的风险。     

基于仿真优化的驳运空箱调运系统研究

运用仿真优化方法对驳运空箱调运系统进行了研究.根据系统作业中存在的不确定性、随机性活动的特点,建立了空箱调运系统的离散事件仿真模型;针对空箱调度规则,建立了数学模型;并运用仿真模型与启发式算法相融合的仿真优化方法进行求解.规划目标是在满足系统作业要求的前提下,以最大化计划渡柜数为目标,优化渡柜规则.即,根据各个码头对空...     

突发事件影响的供应链系统动态仿真

为了研究突发事件对供应链绩效的长期效应,基于系统动力学构建了传统供应链模型、渠道库存控制供应链模型及供应商管理库存供应链模型.以包含一个制造商和一个供应商的二级供应链为研究对象,基于对供应链模型的仿真实验获取了供应链总库存和需求短缺量等绩效指标在无突变风险、生产突变风险和运输突变风险三种情境下的原始数据,通过对供应链绩...     

基于随机需求的两级多期供应链网络规划模型

本文以三级供应链网络为例,研究了具有随机因素的,两级多期决策的供应链网络优化问题.优化的具体内容包括两个方面:供应链节点的选址和相应配送系统的设计.文章首先在现有研究成果的基础上,将模型设计拓展到多期决策领域.接下来,针对因素的随机性问题,应用了蒙特卡罗方法对随机因素进行了模拟和采样.最后,模型的目标函数不仅考虑了最小成本,同时还考虑了顾客满意度.对多目标模型的处理采用了e条件限制法.用这种方法的得到的供应链网络优化结果是一系列帕累托最优解,它使得决策者可以按照自己的偏好做出最后选择.     

考虑价格折扣和运输柔性的库存运输优化研究

在考虑运输能力柔性和销售价格折扣的基础上,建立了零售商主导的分散优化模型、供应商主导的分散优化模型和库存运输联合优化模型,分析得出模型的性质。通过比较研究得出不同决策模式下最优策略和系统绩效的关系。研究表明,零售商主导的分散优化模型的库存成本小于运输库存联合优化模型的库存成本;零售商主导的分散优化模型的运输成本大于运输库存联合优化模型的运输成本;运输库存联合优化供应链的总成本小于零售商主导的供应链总成本。     

分布式多级供应链整合建模及仿真

针对4级供应链结构,构造了多产品、多级结构的采购-生产-分销供应链整合模型。该模型面向供应链各级结构的物流优化,以供应链总成本最小并满足一定容量柔性为目标,确定供应商、工厂、配送中心的最优数目及其选择,以及配送中心和客户区之间的最优配置关系。在此基础上利用LINGO进行仿真求解,对不同场景下的供应链总成本进行了估算,并对容量柔性进行权衡,证明了模型的可行性和有效性。     

Inventory policies analysis under demand patterns and lead times constraints in a real supply chain

This paper reports a study on a real three-echelon supply chain operating in the beverage sector. The authors, starting from the actual supply chain configuration, propose a detailed study of the inventory systems. The test of a comprehensive set of different operative scenarios, in terms of customers’ demand intensity, customers’ demand variability and lead times, becomes a powerful tool for inventory systems analysis along the supply chain. The main objective is the comparison of the actual supply chain configuration with optimistic and pessimistic scenarios for studying the behaviour of different inventory control policies and optimizing the inventory system of each supply chain node. Due to the dynamically changing and stochastic behaviour of the supply chain variables as well as the complex interactions among its actors, the authors have been pushed to implement an advanced simulation model supported by a ‘well-planned’ experimental design. In addition the paper aims to underline the research effort for conceptualizing, modelling, validating and simulating a real stochastic supply chain.     

Distributed supply chain network modelling and simulation: integration of agent-based distributed simulation and improved SCOR model

Agent-based distributed simulation is an efficient methodology for modelling and analysing such complex adaptive systems as dynamic supply chain networks. However, it lacks an acceptable generic standard. Supply chain operations reference (SCOR) model is a cross-functional framework widely accepted as an industry standard. It provides the standard processes, performance metrics, best practices and associated software functionalities for modelling, evaluating and improving supply chain networks. However, it is a static tool. Integration of agent-based distributed simulation and SCOR model can exploit their advantages to form a generic methodology for modelling and simulation of a wide range of supply chain networks. Therefore, this paper proposes a methodology for distributed supply chain network modelling and simulation by means of integration of agent-based distributed simulation and an improved SCOR model. The methodology contains two components: a hierarchical framework for modelling supply chain network based on the improved SCOR model and agent building blocks integrating the standard processes from the SCOR model. The hierarchical framework provides an approach for structure modelling in any level with different granularities based on the improved SCOR model, and allows rapidly mapping a supply chain network into the structure model of a multi-agent system; while agent building blocks are quite useful and convenient to fill the structure model to fulfil its function modelling. With the approach of structure modelling and function filling, not only can the process of agent-based supply chain network modelling be accelerated, but also the built models can be reused and expanded. Because the hierarchical framework is based on the conceptual framework of SCOR model and agent building blocks integrate the standard processes from SCOR model, the proposed methodology is more generic. In addition, the issues of sub-model synchronisation and data distribution management in the agent-based distributed simulation implementation are taken into consideration and the corresponding solutions for these issues are proposed. Finally, an example of a supply chain network is modelled and implemented to illustrate the proposed methodology and related solutions.     

Impact of modelling approximations in supply chain analysis – an experimental study

This paper presents a study of the comparison of the quality of results obtained at different levels of detail using a supply chain simulation. Analysis of supply chain is typically carried out using aggregated information to maintain the level of complexity of the simulation model at a manageable level. Advances in simulation have provided the ability to build comprehensive (detailed), modular models. The quantitative effect of detailed modelling on the corresponding analysis is investigated in this paper. A three-echelon supply chain is analysed using simulation models of varying levels of detail. Using each of these models, four sets of intensive experiments are performed. The first experiment intends to test whether the supply chain dynamics themselves depend on the modelling accuracy that represents the supply chain. The second and third experiments are conducted to test whether the effectiveness of the strategies employed to reduce the supply chain dynamics vary depending on the type (different detail) of model representing the supply chain. In the fourth experiment, statistical techniques are employed to identify which modelling aspect has the most influence on the supply chain dynamics. It is found that the approximations used in modelling, such as delays and capacity, have more impact on the outcome of supply chain analysis than end customer demand. Evidence that both the basic problem (supply chain dynamics) and the solution (strategy to reduce the dynamics) are greatly influenced by the modelling accuracy are presented.     

Analysis of the bullwhip effect in multi-product,multi-stage supply chain systems–a simulation approach

This research aims to develop a simulation approach based on system dynamics modelling (SDM) and adaptive network based fuzzy inference system (ANFIS) for quantifying and reducing the bullwhip effect in a multi-product, multi-stage supply chain. The proposed model is comprised of three groups of variables influencing the bullwhip effect, namely the structure of a supply chain network, supply chain contributions (ordering process in regular situation or when a supplier has a promotion or shortage gaming) and supply chain performances (the number of defects and ordering lead time). As a result, a two layer simulation model is developed with three generic models. The flexibility of this proposed approach is its ability to model various types of ordering policies which are basic inventory policies, material requirement planning (MRP) system and just in time (JIT) approach. The supply chain of a beverage company was selected to validate and demonstrate the flexibility of the proposed model. The findings of the proposed simulation model are consistent with the results obtained from the case study. The error magnitude of the bullwhip effect level varied between 0 and 9% resulting in bullwhip effect reductions of up to 92%. Accordingly, the bullwhip effect levels are significantly decreased by using the proposed simulation model.     

基于LMI的灰色非线性精敏供应链稳定性判定方法

平稳运行是精敏供应链管理的重要基础,针对具有区间灰色非线性特征的精敏供应链系统波动性的难题,以非线性时滞精敏供应链系统为研究基础,建立了灰色非线性精敏供应链系统,采用线性矩阵不等式算法分析其稳定性问题,并获取了一种灰色非线性精敏供应链系统的稳定性判定方法。为验证该方法的有效性和可行性,以医药行业YL集团核心产品的供应链系统为案例分析对象,通过观测两个时点的运行数据,使用Matlab70计算工具,得出［0,20］和［20,40］2个时间段供应链系统的稳定性状态变化图。并假设当客户订货分离点(CODP)下移时,运用同样的观测数据,模拟系统稳定性状态的变化。对比案例分析的结果得出结论：随着CODP从精敏供应链的上游端在下移至下游端时,不仅仅体现的是供应链系统类型的改变,而且更重要的是揭示了精益供应链和敏捷供应链稳定性的影响因素不同,前者受订单量大小程度的影响,而后者由市场需求预测的准确性程度决定。     

Supplier selection and order allocation in closed-loop supply chain systems using hybrid Monte Carlo simulation and goal programming

Supplier selection is an important strategic design decision in closed-loop supply chain systems. In addition, and after identifying the candidate suppliers, optimal order allocations are also considered as crucial tactical decisions. This research presents a multi-objective optimisation model to select the best suppliers and configure manufacturing and refurbishing facilities with the optimal number of parts and products in a closed-loop supply chain network. The objective functions in this research are formulated as total profit, total defective parts, total late delivered parts and economic risk factors of the candidate suppliers. The proposed multi-objective model is solved by hybrid Monte Carlo simulation integrated with three different variants of goal programming method. The effectiveness of the mathematical model and the proposed solution algorithms in obtaining Pareto-optimal solutions is demonstrated in a numerical example adopted from a real case study.     

Selection of Packaging Systems in Supply Chains from a Sustainability Perspective: The Case of Volvo

The purpose of this article is to develop an evaluation model for the selection of packaging systems in supply chains from a sustainability perspective. A theoretical evaluation model for comparing cost efficiency and the environmental impact of packaging systems in supply chains are developed from literature. The model is tested in a case study of a supply chain involving Volvo Car Corporation and Volvo Logistics Corporation, comparing the use of newly developed, one‐way packaging with the sustainability of returnable packaging. The model compares the environmental and economic impacts of two packaging systems in a specific supply chain. The criteria used in the model are (i) packaging fill rate, (ii) packaging material, (iii) transport, (iv) material handling, (v) waste handling and (vi) administration. In the case study, the one‐way packaging resulted in fewer economic and environmental impacts, thereby indicating the importance for companies to question their packaging systems. The model has been tested on one component in a case study. It provides a comparison of the packaging choices included using comparative, but not absolute, figures for the economic and environmental impacts. Managers can use the model to compare packaging systems for component supply and determine the most sustainable packaging from environmental and economic perspectives. The case study indicated that the returnable packaging system commonly used in the automotive industry is not always preferable in terms of sustainability. The article fulfils the need to evaluate the impact of packaging systems on supply chain sustainability in terms of economic and environmental criteria. Copyright © 2012 John Wiley & Sons, Ltd.     

Simulation-based ripple effect modelling in the supply chain

In light of low-frequency/high-impact disruptions, the ripple effect has recently been introduced into academic literature on supply chain management. The ripple effect in the supply chain results from disruption propagation from the initial disruption point to the supply, production and distribution networks. While optimisation modelling dominates this research field, the potential of simulation modelling still remains under-explored. The objective of this study is to reveal research gaps that can be closed with the help of simulation modelling. First, recent literature on both optimisation and simulation modelling is analysed. Second, a simulation model for multi-stage supply chain design with consideration of capacity disruptions and experimental results is presented in order to depict major areas of simulation application to the ripple effect modelling. Based on both literature analysis and the modelling example, managerial insights and future research areas are identified in regard to simulation modelling application to the ripple effect analysis in the supply chain. The paper concludes by summarising the most important insights and outlining a future research agenda.     

Framework for flexibility in dynamic supply chain management

Effective Supply Chain Management (SCM) is a pivotal issue in the dynamically changing business environment. Dynamic SCM requires integrated decision-making amongst autonomous chain partners with effective decision information synchronization amongst them. By exploiting flexibility in supply chain structures, better performance can be achieved. Similarly, by judiciously employing decision flexibility and the associated dynamic control amongst autonomous supply chain nodes, many improvements are possible. The paper presents a study on the role of different flexibility options (i.e. no flexibility, partial flexibility and full flexibility) in a dynamic supply chain model based on some key parameters and performance measures. Supply chain flexibility has significant potential and needs a greater research attention. The paper attempts to advance the knowledge of dynamic control on effective flexibility exploitation in the context of dynamic supply chains. A simulation model of a dynamic supply chain is used for this purpose. The key results are highlighted along with industry implications. Here each supply chain node involves decision-making. Based on the order and sample information available from the immediate buyers or customers, the supplier selection decisions are dynamically made. A seemingly good decision at a stage based on local information often ends up as detrimental not only to the total chain cost, but also to the total costs of the node itself. These observations are important for the designers and managers of the flexible supply chain systems to arrive at appropriate types and a judicious level of flexibility to attain significant improvements in total cost reduction. The modelling of dynamic supply chains with a focus on flexibility can offer enormous potential to the industry. This paper addresses this interesting and challenging domain.     

供应链的冲突机理分析及多代理系统的研究

针对目前对多代理系统在供应链中应用的研究缺乏理论体系的现状,从理论上研究了企业中存在的供应链信息不对称问题,分析了供应链中的冲突机理和principal-agent问题的特点.从供应链信息协调的角度研究了多代理系统在供应链协调中的应用,提出了一个可有效解决信息不对称问题的基于多代理系统的供应链模型,从而对有效实现企业供应链的快速重构和动态协调具有重要的指导意义.