Designation:D5406−22StandardPracticeforRubber—CalculationofProducer’sProcessPerformanceIndexes1ThisstandardisissuedunderthefixeddesignationD5406;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticeprovidesacalculationprocedureandaformatforreportingtheprocessperformanceofamanufactur-ingoperationforarubberorrubberproduct.1.2Thispracticeisspecificallydesignedtobeusedfortechnicallysignificantpropertiesofthefinalproduct.1.3Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1QualityAssurancefortheChemicalandProcessIndustries,AmericanSocietyforQualityControl,ChemicalandProcessIndustriesDivision,ChemicalInterestCommittee,1987.23.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1assignablecausevariation—Seespecialcausevaria-tion.3.1.2commoncausevariation—thatresidualvariationin-herentinanyprocessthat(1)isoperatinginastateofstatisticalcontrol,and(2)isoperatingatsomerecognizedorascertainedleveloftechnologicalcompetence.3.1.3lowerspecificationlimit(LSL)—theproducer’smini-mumpermissiblevalueofanyrelevantmeasuredproductproperty.3.1.4Pp'producer’sprocessperformanceindex—theratioofthedifference(USL−LSL)tothetotalprocessvariation;theindexdoesnotconsiderwheretheprocessiscentered.(See7.4.)3.1.5Ppk'producer’sprocessperformanceindex—theminimumoftworatios:(1)theratioofthedifference(USL−processmean)toone-halfofthetotalprocessvariation,or(2)theratioofthedifference(processmean−LSL)toone-halfofthetotalprocessvariation;themagnitudeoftheminimumindexvalue,usedwiththePp'index,indicateshowwellthepr...
