SPC统计运用及品管实务工具.pptx

統計運用及品管實務工具資料及數據離散型資料(通常)分組/分類是/否,合格/不合格不能計算離散型資料分級极少用很難加以計算連續型資料最常見尺規計算時要很小心連續型資料百分比關係可應用演算法多數公式基礎統計運用概念變異(Variation)變異(Variation)變異(Variation)變異(Variation)變異(Variation)控制變異(Variation)因為用抽樣統計,其結果只是估計,和真實可能有差異.適當抽樣可使統計分析更準確.抽樣方法普通準則均值:一組值算術平均均值:-反应全部值影響-受極值影響嚴重中位數:反應50%序一組數排序後居中數-在計算中无须包含全部值-相對於極值含有“可靠性”眾數值:-在一組資料中最常發生值全距:在一組資料中，最高值和最低值間數值距離變異(s2):每個資料點與均值平均平方偏差標準偏差(s):變異數平方根.量化變動最惯用量The"Rule"stateshowandcanbeusedtodescribetheentiredistribution:·Roughly60-75%ofthedataarewithin1of.·Roughly90-98%ofthedataarewithin2of.·Roughly99-100%ofthedataarewithin3of.Theshapeofadistributioncanbedescribedbyskewness歪斜(denotedby1)andbykurtosis凹凸平坦(denotedby2).母體均值ThemostimportantandusefuldistributionshapeiscalledtheNormaldistribution,whichissymmetric(對稱),uni-modal(單峰),andfreeofoutliers(沒有特異點):ANormalprobabilityplotisacumulativedistributionplotwheretheverticalscaleischangedinsuchawaythatdatafromaNormaldistributionwillformastraightline:第一個屬性:只要知道下面兩項就能够完全描述常態分配:均值標準差常態曲線和其概率常態概率圖資料搜集時重點ContinuousManufacturing(連續)occurswhenanoperationisperformedononeunitofproductatatime.Anassemblylineistypicalofacontinuousmanufacturingenvironment,whereeachunitofproductisworkedonindividuallyandacontinuousstreamoffinishedproductsrollofftheline.TheautomotiveindustryisoneexampleofContinuousManufacturing.Otherexamplesofcontinuouslymanufacturedproductare:·televisionsets,·fastfoodhamburgers,·computers.InContinuousManufacturingthemostimportantvariationisbetweenpartsInLot/BatchManufacturing,thevariationcanoccurbetweenthepartsinalotandbetweenthelots:·Productwithinthesamelotismanufacturedtogether.·Productfromdifferentlotsaremanufacturedseparately.Becauseofthis,eachlothasadifferentdistribution.ThisisimportantbecauseContinuousManufacturingisabasicassumptionformanyofthestandardstatisticalmethodsfoundinmosttextbooksorQChandbooks.ThesemethodsarenotappropriateforLot/BatchManufacturing.DifferentstatisticalmethodsneedtobeusedtotakeintoaccounttheseveralsourcesofvariationinLot/BatchManufacturing.要注意:連續和批量生產所用統計