ASTM_E_1994_-_09_2013.pdf

Designation:E199409(Reapproved 2013)An American National StandardStandard Practice forUse of Process Oriented AOQL and LTPD Sampling Plans1This standard is issued under the fixed designation E1994;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis standard is an abbreviated compilation of the sampling plans presented by H.F.Dodge andH.G.Romig in their classic development of sampling plans for use with the process associated witha continuing supply of products.The so calledAOQLplans provide a means for disposition of productwhether or not the process is in control as well as incentives for process improvement in terms ofreduced sample size as the process average percent defective is lowered.In addition,so called LTPDplans are provided for use with individual lots of product,not necessarily associated with a processstream.The sampling plans and parts of the text given here are taken from the Wiley Classics LibraryEdition of the Dodge-Romig tables(copyright 1998).Additional tables and detailed discussion of theplans,OC curves,and their derivation will be found in that text.2The theoretical development of theDodge-Roming plans will be found in Volumes 8 and 20 of the Bell System Technical Journal3,4andan amplification of the plans is given in Acceptance Sampling in Quality Control.51.Scope1.1 This practice is primarily a statement of principals forthe guidance of ASTM technical committees and others in theuse of Average Outgoing Quality Limit,AOQL,and LotTolerance Percent Defective,LTPD,sampling plans for deter-mining acceptable of lots of product.2.Referenced Documents2.1 ASTM Standards:6E178 Practice for Dealing With Outlying ObservationsE456 Terminology Relating to Quality and Statistics3.Terminology3.1 DefinitionsTerminology E456 provides a more exten-sive list of terms in E11 standards.3.2 average quality protectiona type of protection inwhich there is prescribed some chosen value of average percentdefective in the product after inspection(average outgoingquality limit(AOQL),that shall not be exceeded in the longrun no matter what may be the level of percent defective in theproduct submitted to the inspector.3.3 average outgoing quality(AOQ)the average percentdefective of outgoing product including all accepted lots orbatches,after any defective units found in them are replaced byacceptable units,plus all lots or batches which are not acceptedafter such lots or batches have been effectively 100%in-spected and all defective units replaced by acceptable units.3.4 average outgoing quality limit(AOQL)the maximumof the AOQs for all possible incoming percentages defectivefor the process,for a given acceptance sampling plan.3.5 lot quality protectiona type of protection in whichthere is prescribed some chosen value of limiting percentdefective in a lot(lot tolerance percent defective,(LTPD)andalso some chosen value for the probability(called the consum-ers risk)of accepting a submitted lot that has a percentdefective equal to the lot tolerance percent defective.3.6 lot tolerance percent defective(LTPD)for purposes ofacceptance sampling,the percentage of defective units in a lotfor which the consumer has a stated low probability ofacceptance of the lot.1This practice is under the jurisdiction ofASTM Committee E11 on Quality andStatistics and is the direct responsibility of Subcommittee E11.30 on StatisticalQuality Control.Current edition approved April 1,2013.Published April 2013.Originallyapproved in 1998.Last previous edition approved in 2009 as E1994 09.DOI:10.1520/E1994-09R13.2Available from John Wiley and Sons,Inc.,605 Third Ave.,New York,NY10158.3Dodge,H.F.and Romig,H.G.,“A Method of Sampling Inspection,”The BellSystem Technical Journal,Vol 8,No.10,1924,pp.613631.4Dodge,H.F.and Romig,H.G.,“Single Sampling and Double SamplingInspection Tables,”The Bell System Technical Journal,Vol 20,No.1,1941,pp.161.5Schilling,E.G.,Acceptance Sampling in Quality Control,Marcel Dekker Inc.,NY,1982,pp.372399.6For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.7 Definitions of Terms Specific to This Standard:3.7.1 consumers riskthe probability that a lot whosepercentage defective is equal to the LTPD will be accepted bythe plan.4.Significance and Use4.1 Two general types of tables(Note 1)are given,onebased on the concept of lot tolerance,LTPD,and the other onAOQL.The broad conditions under which the different typeshave been found best adapted are indicated below.4.1.1 For each of the t