【正文】 Error 0 – ?/2 ?/2 =1 – α risk = 2 = 2023/2/7 80 Dr. Weihua Zhou Zhejiang University ? 公差或規(guī)范 Tolerances or specifications – 由工程設(shè)計(jì)或客戶要求決定的可接受值的范圍 Range of acceptable values established by engineering design or customer requirements ? 過程方差 Process variability – 過程中的自然變化 Natural variability in a process ? 過程能力 Process capability – 工序能力是否與標(biāo)準(zhǔn)匹配 Process variability relative to specification 過程能力 /工序能力 Process Capability 2023/2/7 81 Dr. Weihua Zhou Zhejiang University 過程能力 Process Capability Lower Specification Upper Specification Process variability matches specifications Lower Specification Upper Specification Process variability well within specifications Lower Specification Upper Specification C. 過程能力不足 process variability exceeds specifications 2023/2/7 82 Dr. Weihua Zhou Zhejiang University 過程能力指數(shù) Process Capability Ratio 過程能力指數(shù) Cp = 標(biāo)準(zhǔn)區(qū)間寬度 specification width 過程區(qū)間寬度 process width 質(zhì)量標(biāo)準(zhǔn)上限 Upper specification – 質(zhì)量標(biāo)準(zhǔn)下限 lower specification 6? Cp = ???????? ??? 3XU T Lo r 3LT LXm in=C pk如果過程是中心對稱的，則使用 If the process is centered use Cp 如果過程不是中心對稱的，則使用 If the process is not centered use Cpk 2023/2/7 83 Dr. Weihua Zhou Zhejiang University If the process is not centered 3? 70 100 160 030100100,30100160min3,3min1601001606??????? ????????? ?????????????LS LUS LCLS LUS LCpkp2023/2/7 84 Dr. Weihua Zhou Zhejiang University 能力指數(shù)的局限性 Limitations of Capability Indexes 1. 過程可能是不穩(wěn)定的 Process may not be stable 2. 過程輸出可能不是正態(tài)分布的 Process output may not be normally distributed 3. 過程不是中心對稱的，卻使用了 Cp Process not centered but Cp is used 2023/2/7 85 Dr. Weihua Zhou Zhejiang University 舉例 Example 機(jī)器Machine Standard Deviation 標(biāo)準(zhǔn)差 Machine Capability 過程能力 Cp A B C Cp is desirable Cp = 過程基本符合要求 process is barely capable Cp 過程不符合要求 process is not capable ? 工序能力必須大于等于 ，才能符合工序作業(yè)要求。 Use only when the number of occurrences per unit of measure can be counted。我們可以收集樣本數(shù)據(jù)來監(jiān)控延展性的均值和標(biāo)準(zhǔn)差，保證他們是穩(wěn)定的，并且過程不受 特殊原因 影響 Process capability in meeting the design specifications ( to inches) depends on the distribution of spreadability. We can collect sample data to monitor the mean and the standard deviation of spreadability to ensure that they are stable and the process is not subject to special cause variation. 延展性分布 Distribution of spreadability ? ?? ? m ean 1 . 25缺陷 defective 缺陷 defective 2023/2/7 Dr. Weihua Zhou Zhejiang University 50 花生醬問題的樣本數(shù)據(jù) Sample Data for the Peanut Butter Problem Sa m p le A B C D X R 1 0 .94 0 .87 1 .15 1 .01 0 .99 0 .2 8 2 1 .10 1 .05 0 .78 1 .07 1 .00 0 .32 3 1 .23 1 .65 0 .67 1 .21 1 .19 0 .98 4 0 .91 0 .82 1 .20 1 .37 1 .07 0 .55 5 0 .81 0 .76 1 .36 0 .71 0 .91 0 .6 5 6 1 .07 1 .18 1 .24 0 .96 1 .11 0 .28 7 1 .26 1 .09 1 .49 1 .12 1 .24 0. 40 8 1 .11 1 .51 1 .14 0 .90 1 .17 0 .61 9 1 .05 0 .95 0 .90 1 .08 0 .99 0 .1 8 10 1 .60 0 .84 1 .41 1 .30 1 .29 0 .7 6 11 1 .54 0 .96 1 .33 0 .99 1 .21 0 .58 12 1 .33 1 .22 1 .33 1 .46 1 .33 0 .24 13 1 .24 1 .09 1 .31 1 .12 1 .19 0 .22 Sa m p le A B C D X R 14 0 .79 1 .27 1 .07 1 .27 1 .10 0 .48 15 0 .92 1 .47 0 .87 1 .35 1 .15 0. 60 16 0 .78 1 .61 1 .23 1 .00 1 .16 0 .83 17 1 .29 1 .07 1 .60 1 .15 1 .28 0 .53 18 1 .36 0 .98 1 .33 1 .51 1 .29 0 .53 19 1 .20 1 .27 1 .58 1 .18 1 .31 0 .40 20 1 .47 1 .09 1 .59 1 .27 1 .36 0 .50 21 0 .67 1 .35 1 .46 0 .95 1 .11 0 .79 22 1 .05 1 .54 0 .96 1 .53 1 .27 0 .58 23 1 .02 1 .48 1 .31 1 .23 1 .26 0 .46 24 1 .24 1 .25 0 .94 1 .47 1 .22 0 .53 25 1 .12 1 .23 1 .07 1 .12 1 .14 0 .1 6 樣本均值 用來控制延展性的 均值。 If the process is outofcontrol, terminate the process, resolve the assignable causes, and then start the process again 2023/2/7 44 Dr. Weihua Zhou Zhejiang University 正態(tài)分布 Normal Distribution Mean ??? ??? ??? ??? % % ? ? 標(biāo)準(zhǔn)差 Standard deviation 2023/2/7 45 Dr. Weihua Zhou Zhejiang University 樣本分布和過程分布 Sampling distribution and process distribution ? 樣本均值和樣本分布范圍的抽樣統(tǒng)計(jì) The distribution of a sample statistic such as sample mean or sample range ? 即使過程分布不是正常狀態(tài)，樣本分布也是一個(gè)正態(tài)分布。 A rational approach for making investments in quality improvement 2023/2/7 29 Dr. Weihua Zhou Zhejiang University 質(zhì)量證書 Quality Certification ? ISO 9000 –一套基于質(zhì)量管理和質(zhì)量保證，與國際商務(wù)接軌的國際標(biāo)準(zhǔn)。示威者包圍了麥當(dāng)勞設(shè)在新德里的總部，向麥當(dāng)勞餐廳投擲牛糞塊，并洗劫了孟買一家麥當(dāng)勞連鎖店。 ? 保證成本： 維修、退換、補(bǔ)償性服務(wù) ? 訴訟成本： 賠償金、訴訟費(fèi)用 ? 間接損失： 企業(yè)形象、市場份額 生產(chǎn)過程中 最終檢測 用戶 成本 朱蘭 : 缺陷成本占總成本的 5080% 2023/2/7 24 Dr. Weihua Zhou Zhejiang University 檢查成本 Appraisal Costs ? 進(jìn)料檢驗(yàn)費(fèi) ? 工序檢驗(yàn)費(fèi) ? 竣工檢查費(fèi) ? 檢測設(shè)備的折舊費(fèi)、維修費(fèi)。 80%的質(zhì)量問題是由于設(shè)計(jì)原因引起的。費(fèi)根鮑姆 “Quality means best for certain customer conditions. These conditions are (a) the actual use and (b) the selling price of the product.” Feigenbaum ? 質(zhì)量就是使用的適宜性，朱蘭 “Quality is fitness for use.” Juran 2023/2/7 Dr. Weihua Zhou Zhejiang University 4 2023/2/7 Dr. Weihua Zhou Zhejiang University 5 質(zhì)量是什么 What is Quality ? 質(zhì)量領(lǐng)袖簡介 Introduction to Quality Gurus ? Walter Shewhart (休哈特） – 統(tǒng)計(jì)質(zhì)量控制之父 “ Father of statistical quality control” ? W. Edwards Deming （戴明） ? Joseph M. Juran （朱蘭） 2023/2/7 Dr. Weihua Zhou Zhejiang University 6 沃爾特 休哈特 Walter Shewhart (1891 – 1967 ) ? 工程和物理學(xué)位 Trained in engineering and physics ? 長期就職于貝爾實(shí)驗(yàn)室 Long careers at Bell Labs ? 于 1924發(fā)展了 帕累托圖 Developed the first control chart about 1924 2023/2/7 7