ISO 3951:1989
Issue date: 1989 09 14
Sampling procedures and charts for inspection by variables for percent nonconforming
Is complementary to ISO 2859. Object of the methods laid down is to ensure that lots of an acceptable quality have a high probability of acceptance and that the probability of rejection of inferior lots is as high as possible. To be used under the following conditions: inspection procedure to be applied to a continuous series of lots of discrete products supplied by one producer using one production process; only a single quality characteristic is considered which must be measurable on a continuous scale; production is stable and quality characteristic is distributed normally; a contract or standard defines an upper and/or a lower specification limit.