ISO 3951-2:2013 pdf free
ISO 3951-2:2013 pdf free.Sampling procedures for inspection by variables
This part of ISO 3951 is intended to be used as a system employing tightened, normal, and reduced inspection on a continuing series of lots to provide consumer protection while assuring the producer that acceptance will be very likely to occur if quality is better than the AQL.
Sometimes, specific individual plans are selected from this part of ISO 3951 and used without the switching rules. For example, a purchaser may be using the plans for verification purposes only. This is not the intended application of the system given in this part of ISO 3951 and its use in this way should not be referred to as“inspection in compliance with ISO 3951-2″. When used in such a way, ISO 3951-2 simply represents a collection of individual plans indexed by the AQL. The operating characteristic curves and other measures of a plan so chosen shall be assessed individually from the tables provided.
If the series oflots is not long enough to allow the switching rules to be applied, it may be desirable to limit the selection of sampling plans to those, associated with a designated AQL value, that give consumer’s risk quality not more than the specified limiting quality protection. Sampling plans for this purpose can be selected by choosing a consumer’s risk quality and a consumer’s risk to be associated with it.Annex M gives values of consumer’s risk quality levels for the s-method and σ-method corresponding to a consumer’s risk of 10 %.
However, application of this part of ISO 3951 to isolated or short series of lots is deprecated, as the theory of sampling by variables applies to a process. For isolated or short series of lots, it is appropriate and more efficient to use plans for sampling by attributes, such as from ISO 2859-2. (See also Reference [14] in the Bibliography.)ISO 3951-2 pdf download.
