计数型MSAppt课件

1、Measurement Systems Analysis (MSA) Attribute特性数据MSAThe Breakthrough Strategy And Measurement System EvaluationMeasurement Systems Analysis will help us decide if we can adequately measure our output characteristic丈量系统分析有助于确认能否可以胜任丈量输出特性的要求Then after weve improved the process, we will need to assess

2、it again and potentially need to improve it/在改善过程以后，我们需求再次评价丈量系统，以及潜在的丈量系统的改良1.Select Output Characteristic2.Define Performance Standards3.Validate Measurement System确认丈量系统4.Establish Baseline Process Capability5.Define Performance Objectives6.Identify Variation Sources7.Screen Potential Causes8.Dis

3、cover Variable Relationships9.Establish Operating Tolerances Implement Improvements10.Validate Measurement System确认丈量系统11.Determine Final Process Capability12.Implement Process Controls.Module ObjectivesBy the end of this module, the participant should be able to:Discuss the need for an Attribute Me

4、asurement System Analysis讨论属性数据丈量系统分析所需条件Describe the types of Attribute Measurement System Analyses and when to use them 表达属性数据丈量系统分析以及何时运用Perform an Attribute Measurement System Analysis 实施属性数据丈量系统分析.Typical Measurement SystemsAttribute MSAExamplesData collection formSurveyCustomer satisfactionAca

5、demic gradesPlug gages (go/no-go)Thread gages (go/no-go)Visual defect checkNote that often Attribute Measurement Systems involve human judgment Is it reliable for use in decision making?/留意属性数据MSA经常包含人员的断定断定可靠吗？.Purpose Of Attribute MSAAccuracy checks 准确性检查Assess standards against customers requirem

6、ents 评价规范和顾客要求对比Identify how well Measurement System conforms to a “known master /识别丈量系统符合知规范的程度Precision checks 精细性检查To determine if inspectors (Appraisers) across all shifts, machines, lines, etc use the same criteria to evaluate items Reproducibility / 确认检查员(评价者)一切班次、设备、消费线能否运用一样规范评价 再现性To quanti

7、fy the ability of inspectors (Appraisers) or gages to accurately repeat their inspection decisions Repeatability / 量化检查员(评价者)或仪器准确反复检查结果的才干反复性To identify how well inspectors/gages measure a known master (possibly defined by the customer) to ensure no misclassification occurs /识别检查员/仪器丈量知规范(能够是顾客定义)确

8、保没有错误分类的才干How often operators decide to ship truly defective product 多久操作员会将不良品判为合格品？How often operators do not ship truly acceptable product 多久操作员会将合格品判为不良品？To determine areas where 确定以下范围Training is needed 能否需求培训Procedures or Control Plans are lacking 能否缺乏程序或控制方案Standards are not clearly defined 规

9、范能否未定义Gage adjustment or correlation is necessary 仪器调整或相互性是必需的.Attribute Data With Unordered Categories非顺序型的属性数据 KappaSuppose that invoice quality is a key to the process Throughput. In other words, if an invoice is incomplete, the rework required impacts the quantity that can be processed in a day.

10、 Two Appraisers are asked to independently evaluate ten invoices randomly selected from different days. The results of the study are shown below:/假定发票质量是过程输出的关键，换句话说，假设一张发票不完好，再作业就会影响当天的产量。2个评价者独立评价随机在不同日期抽取的10张发票。结果如下所示：Invoice #Appraiser 1 Appraiser 2Agreement? 1BadBadY 2GoodBadN 3GoodGoodY 4BadBa

11、dY 5GoodGoodY 6GoodGoodY 7GoodBadN 8GoodBadN 9GoodGoodY 10GoodGoodYWe could simply look at the percent of the time they agree as metric for between Appraiser agreement: 我们可以只思索评价者断定一致的百分率作为衡量目的But what would that not take into account? 但是还有什么没有思索？_ % agree _ % disagree.Kappa compares the proportion

12、of agreement between Appraisers after removing agreement by chance / Kappa 比较了评价者之间去除了的偶尔性的一致性比率The proportion that the judges are in agreement is Pobserved /判别一致的比率是Pobserved The proportion expected to occur by chance is: 由于偶尔性一致的比率 Pchance = (P Insp1 Good) (P Insp2 Good) + (P Insp1 Bad)(PInsp2 Bad

13、) 1. What would the Kappa be if the judges agreed on every part?/假设每个 零件的断定都一致， Kappa是多少？2. How would you interpret a Kappa of zero?怎样解释Kappa为0？3. What would be the Kappa if the judges never agreed? 假设断定都不一 致Kappa又是多少？Definition Of KappaLets walk through the calculation by hand.How To Calculate Kapp

14、a By HandBuild contingency tableSum columns and rowsCalculate Pobs by adding diagonalCalculate PchanceCalculate KappaPchance = (PR1bad)(PR2bad)+(PR1good)(PR2good) = (.2)(.5)+(.8)(.5) = .5 Pobs - PchanceKappa = 1 - Pchance=(.7-.5)/(1-.5)= 0.4.2.8.5.5 BadGoodAppraiser 1GoodBadAppraiser 2Pobs = .5 + .2

15、 = .7Add3/10 = .32/10 = .20/10 = 05/10 = .5Add Add AddAddHow is this interpreted?.How To Interpret Kappa ResultsThe general rule for interpreting Kappa results are as follows: 解释Kappa的规那么通常如下 0 Non-random disagreement 非随机的不一致 0.9 Excellent Measurement System 极好的丈量系统Remember, consider your Measuremen

16、t System and how well the above criteria might apply.Attribute Data Kappa ExerciseYour company produces documents that are filled with alpha-numeric characters. If a document has one or more numerals (0-9), it is defective. Your mission is to identify the defective documents./他公司的产品是字母与数字混合编排的文件。假设文

17、件中有1个或多个数字(0-9)，就是不合格品。他的义务就是识别不合格的文件。In teams of two, appoint one person to be the data collector The other person is the inspector. The data collection sheet is located on the following page. 2人一组，任命其中一个为数据搜集员，另一个是检查员，数据搜集表在后面一页中The document number is located under each of the 20 documents.The doc

18、uments will be visible for three seconds before automatically advancing. The exercise will be finished in 60 seconds(three seconds/part).共有20个文件，每个显示3秒，然后自动进展下一个。练习在60s内完成(3s/部件).Each Appraiser will perform two trials 每个评价者反复2次Perform analysis in MINITAB per the next slides 进展MTB分析.SVQO6QNITQXNZIZBM

19、QTPZHJKM23! Example !Sample #Kappa ExerciseBegin Kappa exercise.Kappa Exercise Data Collection FormNOTE: Part count of 20 used only for demonstration. Sample size guidelines found on page 13.Kappa Analysis In MINITABPut data into MINITAB, each judges trial in a separate columnTo analyze, go to Stat

20、Quality Tools Attribute Agreement Analysis123Enter Judges (Appraisers) and quantitySelect “Results button and click last option4.Attribute Gage R&R StudyAttribute Gage R&R Study for J1T1, J1T2, J2T1, J2T2Within AppraiserAssessment AgreementAppraiser # Inspected # Matched Percent (%) 95.0% CI 1 20 19

21、 95.0 ( 75.1, 99.9)2 20 18 90.0 ( 68.3, 98.8)# Matched: Appraiser agrees with him/herself across trials. Kappa Statistics Appraiser Response Kappa SE Kappa Z P(vs. 0) 1 b 0.8997 0.2236 4.0238 0.000 g 0.8997 0.2236 4.0238 0.0002 b 0.8000 0.2236 3.5777 0.000 g 0.8000 0.2236 3.5777 0.000Between Apprais

22、ersAssessment Agreement# Inspected # Matched Percent (%) 95.0% CI 20 18 90.0 ( 68.3, 98.8)# Matched: All Appraisers assessments agree with each other.Kappa Statistics Response Kappa SE Kappa Z P(vs. 0) b 0.8833 0.0913 9.6756 0.000g 0.8833 0.0913 9.6756 0.000MINITAB Output Session WindowSince Kappa 0

23、.70 for both Appraisers, both agree well with themselves/ 2个评价者Kappa 0.70，一致度较好 Adequate repeatability/足够的反复性Since Kappa 0.70 for the Between Appraisers,/ 评价者间的Kappa 0.70 Adequate reproducibility/足够的再现性 .Guidelines For Kappa StudiesPlanning 谋划Sample Size样本大小100 samples with two trials per Appraiser

24、/ 100个样品，每个评价者反复2次If only 50-100 samples are available, do three trials per Appraiser/假设只需50-100个样品，每个评价者反复3次 50, understand that you may need very high Kappas to have adequate confidence/ 0)1 -0.058824 0.235702 -0.24957 0.59852 0.035714 0.235702 0.15152 0.43983 -0.107692 0.235702 -0.45690 0.67614 0

25、.000000 0.235702 0.00000 0.50005 0.437500 0.235702 1.85616 0.0317Overall 0.033058 0.132073 0.25030 0.4012Kendalls Coefficient of Concordance Coef Chi - Sq DF P0.670034 10.0505 5 0.0738MINITAB Output Session WindowYou still get the Kappa Statistics, but you wont need to use them here/还是能得到Kappa统计表，但是

26、用不到它们First we need to look at the p-value. Remember, KCC 0, indicates association, if the p-value is small, we accept that KCC 0. The p-value tells you the probability that some association was found purely by chance. This is saying that there is a 7.4% chance a non-zero KCC (some level of associati

27、on) was found by chance alone. You decide based on the amount of risk youre willing to take. A value like 0.05is typical. / 首先要看p值，记住KCC0，表示有联络，假设p值很小，我们接受KCC0。P值表示纯粹由于偶尔而发生联络的能够性。这里表示有的纯粹由于偶尔而发生非0 KCC的时机是7.4%(相互联络的程度)。他的决议取决于他情愿承当的风险。通常设为0.05The KCC is fairly low here, see criteria onnext slide这个KC

28、C比较小，看下一页的规范.How To Interpret Kendalls Coefficient Of Concordance In general, KCC can vary from 0.0 to 1.0/ KCC值普通可以从0变到1The higher the value, the higher degree association among the assessments made by the Appraisers /值越大，评价者的一致性越高How close to 1.0 is needed?需求和1.0多接近？Although very situational depen

29、dent, the general guidelines are as follows:虽然有很多不同情况，但是普通规那么如下0-0.7 Low degree of association, Measurement System needs attention 低程度联络，需关注丈量系统0.7-1.0 Generally acceptable 通常可接纳As stated on the prior page, the p-value for KCC should also be low, generally less than 0.05 This reduces your risk of ge

30、tting an acceptable KCC just by random chance.正如前页所说，KCC的p值应该较小，通常比0.05小 减少由于偶尔呵斥接纳的KCC的风险.Guidelines For Kendalls StudiesPlanning 谋划Sample size 样本大小More is better As your sample size increases, your confidence intervals around your KCC decrease 越多越好 样本大小增大，和KCC有关的置信区间范围减小Collect as many samples as

31、practically possible, 20 minimum is a guideline, 30 is best / 搜集尽能够多的样品，至少20，最好 30 Perform at least two trials per Appraiser 每个评价者至少反复2次Sample part selection 样品选择Parts in the study should represent the full range of variation and thus utilize the full range of the rating scale 研讨的样品能代表变差的整个范围，这样就能运用

32、整个范围的分类规范Execution 实施Parts should be rated in random order independently (no comparisons) /部件应该以随机顺序评价Study should be blind研讨应该是盲测Rating time should be similar to that “normally used评价时间也和 正常运用近似.Guidelines For Kendalls Studies(Contd)Analysis 分析Prior to reviewing the KCC value, check to see that the

33、 p-value is low(generally 0.05) If it is not, add more samples to the study or add another trial / 在看KCC值之前，检查p值能否较小(通常0.05) 如不是，添加样品或添加1次反复Review the repeatability portion first (Within Appraiser), if an Appraisers KCC is very low, they may need improvement (see Improvement below) / 先检查反复性部分(评价者内),

34、假设评价者的KCC很低，那就需求改良(看下面的改良) For Appraisers that have acceptable repeatability, review the reproducibility portion (Between Appraiser) / 如反复性可接纳，检查再现性部分(评价者间)If a “Gold Standard is available (ratings of the samples known by some other means as being “correct), compare each Appraiser to them for “calib

35、ration/ 假设规范知(知的正确的等级)，经过比较每个评价者和知值来校正Use the field in MINITAB, “Known Standard Attribute /用MTB中“Known Standard Attribute一栏Improvement 改良If the Within Appraiser KCC scores are low, that Appraiser may need training. Do they understand the rating scale? Are the instructions clear to them? / 评价者内 KCC值较

36、低，那么就需求培训，他们能否了解分类规范？能否清楚作业指点书？If the Between Appraiser KCC scores are low, each Appraiser may have a differing definition of the rating scale A standardized definition can improve this situation /评价者间 KCC 值较低，那么每个评价者对零件分类的定义不同规范定义可以改动这种情况If improvements are made, the study should be repeated to con

37、firm improvements have worked /假设已进展改良，还需求再次研讨以确认改良有效.Objectives ReviewThe participant should be able to:Discuss the need for an Attribute Measurement System Analysis讨论属性数据丈量系统分析所需条件Describe the types of Attribute Measurement System Analyses and when to use them 表达属性数据丈量系统分析以及何时运用Perform an Attribut

38、e Measurement System Analysis 实施属性数据丈量系统分析.AppendixAttribute MSA MethodStep 1:Select a minimum of 30 parts from the process 至少选择30个部件50% of the parts in your study should have defects/ 50%有缺陷50% of the parts should be defect-free/ 50%没有缺陷If possible select border line (or marginal) good and bad samp

39、les / 尽能够选择界限附近的好的和不好的样品Step 2:Identify the appraisers which should be qualified / 选择有资历的评价者Step 3:Have each appraiser, independently and in random order, assess these parts and determine whether or not they pass or fail / 每个评价者随机评价部件，确认能否经过或不经过Step 4:Enter the data into Excel or MINITAB to report t

40、he effectiveness of the attribute measurement system / 输入Excel或MTB 报告属性数据MSA的有效性Step 5:Document the results. Implement appropriate actions to fix the inspection process if necessary / 结果文件化，如有必要，进展相应的改善Step 6:Re-run the study to verify the fix / 再运转MSA，验证改善有效Note: A 30-piece sample will yield an est

41、imate of appraiser efficiency and capability which has a fair amount of uncertainty. Typically a larger sample is not needed because the appraisal process is obviously ineffective. The Excel spreadsheet can handle up to 100 samples.Attribute MSA Supplemental FilesAttribute MSA - Excel MethodAllows f

42、or R&R analysis within and between appraisers 可以评价者内和评价者间的反复性和再现性研讨Test for effectiveness against standard 检验和规范值比较的有效性Limited to nominal data at two levels 仅限于2程度的nominal 数据.DATE:1/4/2001Attribute Legend5 (used in computations)NAME:Acme Employee1PassPRODUCT:Widgets2FailBUSINESS:Earth ProductsKnown

43、PopulationSample #AttributeTry #1Try #2Try #1Try #2Try #1Try #21PassPassPassPassPassPassPass2PassPassPassPassPassPassPass3PassPassPassPassPassPassPass4PassPassPassPassPassFailPass5FailFailFailFailFailPassFail6FailPassPassPassPassPassPass7PassPassPassPassPassPassPass8PassPassPassPassPassPassPass9Fail

44、FailFailFailFailFailFail10PassPassPassPassPassPassPass11PassPassPassPassPassPassPass12PassPassPassPassPassPassPass13PassPassPassPassPassPassPass14PassPassPassPassPassFailPass15FailFailFailFailFailPassFail16PassPassPassPassPassPassPass17PassPassPassPassPassPassPass18PassPassPassPassPassPassPass19Fail

45、FailFailFailFailFailFail20PassPassPassPassPassPassPass21PassPassPassPassPassPassPass22PassFailFailPassPassPassPass23PassPassPassPassPassPassPass24PassPassPassPassPassFailPass25FailFailFailFailFailFailFail26PassPassPassPassPassPassPass27PassPassPassPassPassPassPass28PassPassPassPassPassPassPass29FailFailFailFailFailFailFail30PassPassPassPassPassPassPassOperator #1Operator #2Operator #3Attribute MSA ExampleOpen file: MSA-Attribute.xls.Scoring Example100% is target for all scores 57.14%SCREEN % EFF