DEMATEL方法介绍.ppt

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1、Decision making trial and evaluation laboratoryDEMATEL,2010暑期培训班 张文力,1,References,S.M.Seyed-Hosseini*,N.Safaei,M.J.Asgharpour Tongji University 吉林大学长春理工大学,2,DEMATEL起源？,时间：November 2005作者：S.M.Seyed-Hosseini*,N.Safaei,M.J.AsgharpourIran发表：RELIABILITY ENGINEERING&SYSTEM SAFETY名称：Reprioritization of fai

2、lures in a system failure mode and effects analysis decision making trial and evaluation laboratory technique,3,DEMATEL中文:决策试行与评价实验室。an effective approach for analyzing relation between components of a system in respect to its type(direct/indirect)and severity它是进行因素分析与识别的一种有效的方法。例1一种运用图论与矩阵工具进行系统因素分

3、析的方法，是通过系统中各因素之间的逻辑关系与直接影响矩阵，计算出每个因素对其他因素的影响程度以及被影响度，从而计算出每个因素的中心度与原因度。这种方法是充分利用专家的经验和知识来处理复杂的社会问题，尤其对那些要素关系不确定的系统更为有效。,DEMATEL是什么？,下一页,4,归根到底,DEMATEL是对(1)失效模型failure mode and effects analysis(2)影响因素(3)决策标准排序！,DEMATEL诞生的原因，见文章1,见例1,传统的多目标决策矩阵：看各个标准之间的关系,排序之后可以做什么?例如(1)应该更关注哪个失效模型?(2)哪个影响因素对公司的业绩影响最大

4、?(3)怎样给决策标准赋予权重?,5,DEMATEL 输入什么，得到什么?i,例1：怎样培养一个好学生？(1)专家说四大因素:A自身努力，B家庭因素，C学校因素，D社会因素(2)专家说各要素之间的关系,传统方法是否考虑了各因素之间的关系?,A,D,C,B,哪个因素更重要?,5,4,3,2,1,观察：BA:家庭因素直接影响一个人的努力程度DA:社会因素直接影响一个人的努力程度D BA：社会因素通过影响家庭，最终影响个人努力程度,不仅有直接关系还有间接关系,6,(3)我们通过(2)得到一个矩阵:直接影响矩阵M,DEMATEL 输入什么，得到什么?ii,A,D,C,B,5,4,3,2,1,注意用词！

5、,(4)把(3)中得到的矩阵标准化，得到矩阵M,怎样标准化？文章1,7,DEMATEL 输入什么，得到什么?iii,(5)通过一系列计算得到综合影响矩阵M,每行元素分别求和,每列元素分别求和,最后根据R+C 或者R-C对ABCD排序,注意用词！,R+C 或者R-C 的具体含义？,8,问题：,(1)DEMATEL为什么诞生？(2)中间的计算过程？(3)排序的依据？(4)DEMATEL的优点？,文章1逐一解答,9,Reprioritization of failures in a system failure mode and effects analysis decision making tr

6、ial and evaluation laboratory technique,作者：S.M.Seyed-Hosseini*,N.Safaei,M.J.Asgharpour Industrial Engineering Department,Iran University of Science and Technology,Narmak,Tehran,16844,IranAvailable online 10 November 2005发表：RELIABILITY ENGINEERING&SYSTEM SAFETY,最早提出dematel,失效模式与影响分析,10,综述：,研究意义（为什么？）

7、some of inherently shortcomings of conventional Risk Priority Number(RPN)method and like.失效模式与影响分析这个领域传统的RPN 方法存在一定缺陷。研究目的（做什么？）an effective methodology related to decision making eld has been developed for reprioritization of failure modes in a system Failure Mode and Effects Analysis(FMEA)for corr

8、ective actions.优化失效模式与影响分析中失效模式的顺序用来纠正偏差.研究内容（怎么做？）Decision Making Trial and Evaluation Laboratory(DEMATEL)analyzing relation between components of a system in respect to its type(direct/indirect)and severity.分析各元素之间直接+间接的关系研究结果 The demonstrated results have shown that DEMATEL method can be an efcie

9、nt,complementary and condent approach for reprioritization of failure modes in a FMEA.有效、完备、可信,11,背景知识：失效模式与影响分析-FMEA,起源：1960，航空工业。研究系统中每一个组成部分可能的失效模式，确定各个失效模式的后果或对系统可靠性的影响，并按其影响的严重程度进行分类的分析方法。用途：某个系统对可靠性和安全性要求很高。预防错误发生+及时纠错(1)what might go wrong?什么地方可能出问题(2)What might cause it to wrong?什么原因引起的(3)An

10、d what effect would it have?会造成怎样的影响,12,传统的FMEA分析方法RPN,risk priority number风险优先数 Traditionally,the prioritization of failures for corrective actions is performed by eveloping a risk priority number(Ford Motor Company,1988).传统对错误排序的方法 RPN Number=S*O*D,依据这个值的大小来排序,S：severity of its failure effect 严重性O

11、：probability of the failure-mode occurrence 可能性 D：probability of the failure being detected 被发现的可能性下一页 例子,13,RPN打分：,S,O,D,14,RPN的缺点,(1)the RPN elements are not equally weighted with respect to one another in terms of risk.(2)the RPN scale itself has some non-intuitive statistical properties.,DEMATEL

12、诞生！,例如：A:RPN 9X3X2=54 B:RPN 4X5X6=120A一旦发生就会产生严重后果，应该优先处理，但是RPN值很小,平均值是166不是500中点不在500有1000种可能的RPN值，实际上只有120种,15,DEMATEL methodology i,16,DEMATEL methodology ii,各行求和，找最大，此处10,17,DEMATEL methodology iii,有证明不详讲，计算过程下一页,含义；(1)B到E有一条直接或者间接通路(2)B对E施加影响，影响因子0.098 失效模式与影响(3)B与E的重要程度，B比E重要0.098 决策标准,18,M计算过

13、程excel,M=,E-M=,(E-M)-1=,M*(E-M)-1=,19,DEMATEL methodology iv,R+C和R-C的含义，下一页,20,DEMATEL methodology v,R,C,R+C,R-C的含义：,R+C：degree of relation between each alternative with others and alternatives having more values of R+C have more relationship with another and those having little values of R+C have l

14、itter relationship with others.与其他元素的关系，值越大，关系越密切。R-C：indicates severity of inuence for each alternative.having more values of R-C have higher inuence to another and are assumed to have higher priority and those having little values of R-C receiving more inuence from another are assumed to have lowe

15、r priority.值大对其他元素施加很大影响，自己很少受其他元素影响。优先级由此判定.R-C0:dispatcher R-C0:receiver,以B为例：R：B 对其他元素施加的影响C：其他元素对B施加的影响,21,DEMATEL methodology vi,As a result,the prioritization of alternatives in terms of R-C is as BCEDA.,22,DEMATEL 优点：,considering indirect relationships in relation analyzecapability of cluster

16、ing alternatives in large systems with many failure modesRPN or similar approaches can be as an input data for DEMATEL method.与其它方法结合allocating as possible as a unique rank number to each alternative 例子 下一页,23,优点(3)区分度更好,CF24应该CF27重要,RPN体现不出来，原因下一页,24,CF24 has a severity of inuence 360 on MF3 and a

17、severity of inuence 360 on MF5 too.However,according to row 32,CF27 has only a severity of inuence 392 on MF4.It is notable that values 360 and 392 are relative large value in RPN implementation in Table 7.,25,Obviously,the performance of proposed method is depends on input data,i.e.weights matrix.T

18、herefore,other methods such as RPR can be considered for this method.Also DEMATEL can be considered in Fuzzy or probability environments that suggested for further researches.,DEMATEL 未来的发展,26,Assessing the architectural design services by using DEMATEL approach,作者：Shouming Chen School of Economics

19、and Management Tongji University发表：2009 International Conference on computational Intelligence and Natural Computing,提供一个case study 加深印象,27,Architectural Design Companies,what factors should be used to assess the service?a more precise weigh vector?,是什么在影响建筑设计公司的服务质量？,28,(1)Delphi method 确定6个主要因素,Th

20、e committee chose six main factors for the evaluation of design service,which are:quality(F 1),delivery time(F 2),technological capability(F 3),reputation(F 4),flexibility(F 5),price(F 6).,29,(2)Delphi method 确定6个因素间的相互关系,用来标准化,30,(3)标准化direct-relation matrix,31,(4)根据公式得到Total relation matrix，计算D+R,D-R,32,(5)本文的特别之处,(1)用D+R来排序(2)顺带求出了6个影响因素的权重,结论在这里,33,Thank you for your attention.,34,