Acceptable quality limit
The acceptable quality limit (AQL) is the worst tolerable process average in percentage or ratio, that is still considered acceptable: that is, it is at an acceptable quality level. Closely related terms are the rejectable quality limit and level (RQL). In a quality control procedure, a process is said to be at an acceptable quality level if the appropriate statistic used to construct a control chart does not fall outside the bounds of the acceptable quality limits. Otherwise, the process is said to be at a rejectable control level.
The usage of the abbreviation AQL for the term Acceptable Quality Level has recently been changed in the standards issued by at least one national standards organization (ANSI/ASQ) to relate to the term Acceptance Quality Level. It is unclear whether this interpretation will be brought into general usage, but the underlying meaning remains the same.
An acceptable quality level is an inspection standard describing the maximum number of defects that could be considered acceptable during the random sampling of an inspection. The defects found during inspection are sometimes classified into three levels: critical, major and minor. Critical defects are those that render the product unsafe or hazardous for the end user or that contravene mandatory regulations. Major defects can result in the product's failure, reducing its marketability, usability or saleability. Lastly, minor defects do not affect the product's marketability or usability, but represent workmanship defects that make the product fall short of defined quality standards. Different companies maintain different interpretations of each defect type. In order to avoid argument, buyers and sellers agree on an AQL standard, chosen according to the level of risk each party assumes, which they use as a reference during pre-shipment inspection.
- ^ a b Dodge, Y. (2003) The Oxford Dictionary of Statistical Terms. OUP. ISBN 0-19-920613-9
- ^ Chandrupatla, T.R. (2009) Quality and Reliability in Engineering, CUP. ISBN 978-0-521-51522-1
- ^ ANSI/ASQ Z1.4-2008 Sampling Procedures and Tables for Inspection by Attributes.
- ^ http://www.aqlinspectorsrule.com/Z1-4-2008.html AQL Inspectors Rule
- Hughes, Charles C. (2005). State construction quality assurance programs. Washington, D.C: Transportation Research Board. ISBN 0-309-09749-5. http://books.google.co.uk/books?id=O4Ap0idKEccC&pg=PA73&dq=RQL+quality&cd=1#v=onepage&q=RQL%20quality&f=false.
- Pyzdek, Thomas (1989). What every engineer should know about quality control. New York: M. Dekker. ISBN 0-8247-7966-5. http://books.google.co.uk/books?id=NKpitRCwolgC&pg=PA161&dq=RQL+quality&cd=5#v=onepage&q=RQL%20quality&f=false.
Wikimedia Foundation. 2010.
Look at other dictionaries:
deterioration limit — A limit placed on a particular product characteristic to define the minimum acceptable quality requirement for the product to retain its NATO code number … Military dictionary
Indoor air quality — (IAQ) is a term referring to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. IAQ can be affected by microbial contaminants (mold, bacteria), gases (including… … Wikipedia
Automated Quality control of meteorological observations — A meteorological observation at a given place can be inaccurate for a variety of reasons, such as a hardware defect. Quality control can help spot which meteorological observations are inaccurate.One of the main automated quality control program… … Wikipedia
Aql — may refer to: * Aql, an Islamic term * Acceptable Quality Limit, the worst case quality level, expressed as a percentage of defects in a population, that is still considered acceptable. * aql.com, a UK communications provider for email to SMS,… … Wikipedia
Control limits — Control limits, also known as natural process limits, are horizontal lines drawn on a statistical process control chart, usually at a distance of ±3 standard deviations of the plotted statistic from the statistic s mean. Control limits should not … Wikipedia
List of mathematics articles (A) — NOTOC A A Beautiful Mind A Beautiful Mind (book) A Beautiful Mind (film) A Brief History of Time (film) A Course of Pure Mathematics A curious identity involving binomial coefficients A derivation of the discrete Fourier transform A equivalence A … Wikipedia
statistics — /steuh tis tiks/, n. 1. (used with a sing. v.) the science that deals with the collection, classification, analysis, and interpretation of numerical facts or data, and that, by use of mathematical theories of probability, imposes order and… … Universalium
MPEG-1 — Moving Picture Experts Group Phase 1 (MPEG 1) Filename extension .mpg, .mpeg, .mp1, .mp2, .mp3, .m1v, .m1a, .m2a, .mpa, .mpv Internet media type audio/mpeg, video/mpeg Developed by ISO, IEC Type of format audio, vid … Wikipedia
Engineering tolerance — is the permissible limit or limits of variation in a physical dimension, a measured value or physical property of a material, manufactured object, system, or service, other measured values (such as temperature, humidity, etc.). in engineering and … Wikipedia
Human rights in Japan — Japan This article is part of the series: Politics and government of Japan … Wikipedia