6s的意義與計(jì)算

1、6s的意義與計(jì)算 s 是一個希臘字母, 用來 描 述 過程的變差 6s 最初由 Motorola 公司發(fā)起, 逐漸 被越來越多的世界級大公司所采用68.2% 的數(shù)據(jù)落在1s 以內(nèi)95.4% 的數(shù)據(jù)落在2s 以內(nèi)99.7% 的數(shù)據(jù)落在3s 以內(nèi)99.99999975% 的數(shù)據(jù)落在6s 以內(nèi)3 2 1 1 2 3LSL下限USL上限平均值m或目的值Ts個數(shù)的計(jì)算(延續(xù)數(shù)據(jù)Z =sMinUSL-T, T-LSL Z=3Cpk過程的漂移短期4短期3短期2短期1長期s的個數(shù) Zlt(長期=Zst短期-1.5計(jì)算s個數(shù)的概念與公式Unit: 單元，被研討對象的根本單位。如一件產(chǎn)品、一次效力、一個過程等。D

2、efect: 缺陷，任何未到達(dá)要求的特性DPU (Defects per unit) = Defects / Unit = 缺陷數(shù)/單元數(shù)PPM (Defects per Million Units) = Defects / Unit x 106 =缺陷數(shù)/單元數(shù) X 106 )TOP (Total Opportunities) = Units * Opportunities (總時機(jī)=單元數(shù) X 每單元發(fā)生缺陷的時機(jī)DPO (Defects per Opportunity)=Defects/TOP (每個時機(jī)中產(chǎn)生的缺陷數(shù)=缺陷數(shù)/總時機(jī)DPMU(Defects per million un

3、its)=DPUx 106 每百萬單元中的缺陷數(shù)DPMO (Defects per Million Opportunities) = Defects / TOP x 106 = 缺陷數(shù) / TOP x 106First Pass Yield(一次合格率)=全過程中未產(chǎn)生任何缺陷的單元數(shù)/總單元數(shù)Rolled Yield (單元的缺陷數(shù)為零的幾率 The likelihood that any given unit of product will contain 0 defects) YRT= e -DPU YRT = P(ND) * P(ND) * P(ND) *.P(ND)n PND) 表示

4、零缺陷的幾率Ynorm (Normalized Yield 正態(tài)合格率=1-DPO= n YRT (延續(xù)過程的平均合格率 n=過程的個數(shù)Zlt=NormSinv(Ynorm) 在電子表格Excel 的函數(shù) fx 中的統(tǒng)計(jì)類中， 或查表Zst=Zlt+1.5計(jì)算s個數(shù)的概念與公式非延續(xù)數(shù)據(jù)計(jì)算s個數(shù)實(shí)例M(每單元產(chǎn)生缺陷的時機(jī) =50Units單元數(shù) =1000Defects缺陷數(shù) =500TOP=MxUnits =50000DPO=Defects/TOP =0.01DPMO=DPOx106 =10000Ynorm=1-DPO =0.9900Zlt=NormSinv(Ynorm) =2.33Zs

5、t=Zlt+1.5 =3.8393.32%Long-Term YieldLong-Term Yield42308,537366,8076,210523363.4不同s 個數(shù)的比較(Distribution Shifted 1.5s)sPPM過程才干DPMO345671,000,000100,00010,0001,0001001012Sigma 的個數(shù)PPMThe Basic Objective普通公司Best-in-Class世界級優(yōu)秀公司- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Process Ent

6、itlement 目的Sweet Fruit 最甜的果實(shí)Design for ManufacturabilityBulk of Fruit 大量的果實(shí)Process Characterization and Optimization過程優(yōu)化Low Hanging Fruit 底處的果實(shí)Seven Basic Tools 統(tǒng)計(jì)七工具Ground Fruit 掉到地上的果實(shí)Logic and Intuition根本常識- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -We dont know what we don

7、t knowWe cant act on what we dont knowWe wont know until we searchWe wont search for what we dont questionWe dont question what we dont measureHence, We just dont know WHAT LEVEL ARE YOU?6s的意義與計(jì)算 s 是一個希臘字母, 用來 描 述 過程的變差 6s 最初由 Motorola 公司發(fā)起, 逐漸 被越來越多的世界級大公司所采用68.2% 的數(shù)據(jù)落在1s 以內(nèi)95.4% 的數(shù)據(jù)落在2s 以內(nèi)99.7% 的數(shù)

8、據(jù)落在3s 以內(nèi)99.99999975% 的數(shù)據(jù)落在6s 以內(nèi)3 2 1 1 2 3LSL下限USL上限平均值m或目的值Ts個數(shù)的計(jì)算(延續(xù)數(shù)據(jù)Z =sMinUSL-T, T-LSL Z=3Cpk過程的漂移短期4短期3短期2短期1長期s的個數(shù) Zlt(長期=Zst短期-1.5計(jì)算s個數(shù)的概念與公式Unit: 單元，被研討對象的根本單位。如一件產(chǎn)品、一次效力、一個過程等。Defect: 缺陷，任何未到達(dá)要求的特性DPU (Defects per unit) = Defects / Unit = 缺陷數(shù)/單元數(shù)PPM (Defects per Million Units) = Defects /

9、Unit x 106 =缺陷數(shù)/單元數(shù) X 106 )TOP (Total Opportunities) = Units * Opportunities (總時機(jī)=單元數(shù) X 每單元發(fā)生缺陷的時機(jī)DPO (Defects per Opportunity)=Defects/TOP (每個時機(jī)中產(chǎn)生的缺陷數(shù)=缺陷數(shù)/總時機(jī)DPMU(Defects per million units)=DPUx 106 每百萬單元中的缺陷數(shù)DPMO (Defects per Million Opportunities) = Defects / TOP x 106 = 缺陷數(shù) / TOP x 106First Pas

10、s Yield(一次合格率)=全過程中未產(chǎn)生任何缺陷的單元數(shù)/總單元數(shù)Rolled Yield (單元的缺陷數(shù)為零的幾率 The likelihood that any given unit of product will contain 0 defects) YRT= e -DPU YRT = P(ND) * P(ND) * P(ND) *.P(ND)n PND) 表示零缺陷的幾率Ynorm (Normalized Yield 正態(tài)合格率=1-DPO= n YRT (延續(xù)過程的平均合格率 n=過程的個數(shù)Zlt=NormSinv(Ynorm) 在電子表格Excel 的函數(shù) fx 中的統(tǒng)計(jì)類中，

11、 或查表Zst=Zlt+1.5計(jì)算s個數(shù)的概念與公式非延續(xù)數(shù)據(jù)計(jì)算s個數(shù)實(shí)例M(每單元產(chǎn)生缺陷的時機(jī) =50Units單元數(shù) =1000Defects缺陷數(shù) =500TOP=MxUnits =50000DPO=Defects/TOP =0.01DPMO=DPOx106 =10000Ynorm=1-DPO =0.9900Zlt=NormSinv(Ynorm) =2.33Zst=Zlt+1.5 =3.8393.32%Long-Term YieldLong-Term Yield2308,537366,80746,210523363.4不同s 個數(shù)的比較(Distribution Shifted 1.

12、5s)sPPM過程才干DPMO345671,000,000100,00010,0001,0001001012Sigma 的個數(shù)PPMThe Basic Objective普通公司Best-in-Class世界級優(yōu)秀公司- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -We dont know what we dont knowWe cant act on what we dont knowWe wont know until we searchWe wont search for what we dont questionWe dont question what we dont measureHence, We just dont know Low Hanging Fruit 底處的果實(shí)Seven Basic Tools