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分布正態(tài)分布Normal Distribution文檔密級:內(nèi)部公開使用標(biāo)準(zhǔn)差決定控制上限及下限 ,如鐘狀曲線 .To determine UCL LCL, use standard deviation (s) just like the bell curve!UCL = Average + 3sAverageLCL = Average 3s+3s3s3s+3s如何將這些應(yīng)用在控制圖如何將這些應(yīng)用在控制圖 ?How does this relate to control charts?設(shè)定控制限設(shè)定控制限Setting Control Limits將鐘狀曲線轉(zhuǎn) 90度Flip the bell curve on it’s sideAverage3s +3s2s +2s1s +1sLCL UCL3s+3s2s+2s1s +1sLCLUCLAverage3s+3s2s+2s1s+1sLCLUCLAverage設(shè)定控制限設(shè)定控制限Setting Control Limits這是什么意思 ?What does it all mean?UCL=Average +3sLCL=Average 3s3s+3s2s+2s1s+1sAverageLCLUCL文檔密級:內(nèi)部公開控制限控制限 控制上控制上 ,下限下限Control Limits UCL, LCL若流程受到控制 :If your process is in control:%的數(shù)據(jù)將會在控制上限及下限之間 . % of the data points will be between the UCL and LCL.216。數(shù)據(jù)沒有特定的圖樣 ,隨機(jī)的 . Data points will show no pattern = random.216。大部分?jǐn)?shù)據(jù)會趨向平均值 . Most data points will be close to the average.216。數(shù)據(jù)應(yīng)有一半在平均值以上及一半在以下 . Data points be 50/50 above and below average.標(biāo)準(zhǔn)差如何影響標(biāo)準(zhǔn)差如何影響控制上限及下限控制上限及下限How Standard Deviation Affects UCL LCL將圖 1至圖 4與正確的標(biāo)準(zhǔn)差連線那一個標(biāo)準(zhǔn)差會在控制圖上定出最寬的控制限規(guī)格規(guī)格 限Specification Limits客戶 ,供應(yīng)商或內(nèi)部工程要求Customer, supplier or internal engineering requirements包括 :Include :v目標(biāo)或中間值 (最理想的 ) target or nominal value (the ideal!)v在目標(biāo)值兩旁可接受的變異 allowable variation on either side of the target value規(guī)格上限 = 目標(biāo)值 + 可接愛的變異USL = target + allowable variation規(guī)格下限 = 目標(biāo)值 可接受的變異LSL = target allowable variation例子例子 酸濃度酸濃度Example Acid Concentration規(guī)格是 130克 /升 +/30克升Specification is 130 grams/liter +/ 30 grams/liter216。 規(guī)格上限 =目標(biāo)值 +可接受的變量USL = target + allowable variation130 + 30 = 160216。 規(guī)格下限 =目標(biāo)值 可接受的變異LSL = target allowable variation130 30 = 100216。 可接受變異的總值 =規(guī)格上限 =規(guī)格下限Total allowable variation = USL LSL160 100 = 60我們可以量度能力嗎我們可以量度能力嗎 ?Can We Measure Capability?USLLSL目標(biāo)Target可接受的變異Allowable Variation下圖 =規(guī)格Picture below = specifications正態(tài)分布 (鐘狀曲線 )=流程Normal distribution (bell curve) = process實際變異Actual Variation流程中心點Process CenterCp 必須大于必須大于 1Cp Should Be Greater Than 1顯示實際變異少于可接受變異Indicates actual variation is less than allowable variation.LSLUSLLSLUSLLSLUSLCp大于 1Cp greater than 1Cp = 1Cp少于 1Cp less than 1Cp 量度流程分布量度流程分布Cp Measure