# ISO 8423:1991 — Withdrawn and superseded ISO standards

For ISO 8423:1991, item title is Sequential sampling plans for inspection by variables for percent nonconforming (known standard deviation); status code is 9599; successor is ISO 8423:2008 | ISO 3951-5:2006; withdrawn / published date is 1991-11-07, recorded from its source on 2026-08-05.

- **Identifier:** ISO 8423:1991 _(verified: appears in the quote below)_
- **Item title:** Sequential sampling plans for inspection by variables for percent nonconforming (known standard deviation) _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO 8423:2008 | ISO 3951-5:2006
- **Withdrawn / published date:** 1991-11-07 _(verified: appears in the quote below)_

## What the source says

> 15601,IS,,ISO 8423:1991,Sequential sampling plans for inspection by variables for percent nonconforming (known standard deviation),Plans d'échantillonnage progressif pour le contrôle par mesures des pourcentages de non conformes (écart-type connu),1991-11-07,1,['03.120.30'],ISO/TC 69/SC 5,9599,,"[41992,39294]","['en','fr']",39,<p>Applies if all of the following conditions are satisfied: a) inspected are continuing series of lots of discrete items supplied by one producer from one production process; b) only a single quality characteristic x is taken into consideration; c) production is stable and x has a known standard deviation; d) an upper or lower limit (or both) is defined.</p>

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).