ISO 2859-5-2005 PDF

Full title and description

Sampling procedures for inspection by attributes — Part 5: System of sequential sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection. This part of ISO 2859 specifies sequential sampling schemes that supplement the ISO 2859-1 acceptance-sampling system; it provides statistically equivalent sequential plans that reduce average sample numbers while preserving the AQL-based operating characteristics for lot-by-lot inspection.

Abstract

ISO 2859-5:2005 contains sequential sampling schemes indexed by the acceptance quality limit (AQL) intended to supplement the ISO 2859 series for inspection by attributes. The document explains the purpose and application of sequential plans, highlights their advantages in reducing average sample numbers (especially for very good quality levels), and introduces practical rules (including switching between normal/tightened/reduced inspection and curtailment limits) for application to continuing series of lots.

General information

• Status: Published (International Standard)
• Publication date: June 2005 (2005‑06)
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 03.120.30 (Application of statistical methods)
• Edition / version: Edition 1 (2005)
• Number of pages: 43 pages (English edition)

Core bibliographic and lifecycle details above are those recorded by ISO for ISO 2859-5:2005.

Scope

This part of ISO 2859 specifies sequential sampling schemes indexed by AQL for lot‑by‑lot inspection. The schemes are applicable (but not limited) to inspection of end items, components and raw materials, operations, materials in process, supplies in storage, maintenance operations, data/records and administrative procedures. The procedures are designed for use on a continuing series of lots long enough for the prescribed switching rules (normal/tightened/reduced inspection) to be applied; isolated lots should be assessed using the guidance in ISO 2859-2.

Key topics and requirements

• Sequential sampling plans indexed by AQL that are statistically equivalent to ISO 2859‑1 single sampling plans but with much lower average sample numbers for good-quality lots.
• Switching rules between reduced, normal and tightened inspection based on recent lot history (to give incentive for good quality and enhanced protection when quality deteriorates).
• Curtailment/upper‑limit provisions to control excessive sample sizes (the standard introduces practical limits on maximum inspection effort compared with classical sequential plans).
• Tables and plans for normal, tightened and reduced inspection and average sample numbers for the presented sequential schemes.
• Guidance on applicability, limitations and organisational considerations (e.g., sampling logistics, test duration and when sequential plans are advantageous vs. single/double sampling).

Technical details, tables and annexes that provide the specific sequential plans and average sample‑number data are given in the standard.

Typical use and users

Manufacturers, quality engineers, inspectors and procurement organizations that perform lot-by-lot acceptance inspection and require statistically defensible sampling with minimized average inspection effort will use this part of ISO 2859. It is especially useful when product/process quality is high (very low nonconformity rates) and where conventional single-sample plans would require impractically large sample sizes. Users include industrial quality departments, independent inspection bodies, standards bodies and statistical consultants.

Related standards

ISO 2859-5 is part of the ISO 2859 series. Closely related parts and complementary standards include ISO 2859-1 (sampling schemes indexed by AQL for lot-by-lot inspection), ISO 2859-2 (plans for isolated lots), ISO 2859-10 (introduction to the series) and ISO 3951 (sampling procedures for inspection by variables, including part 5 for sequential plans by AQL). This part is intended to be used in conjunction with ISO 2859-1 and the other series parts depending on the inspection context.

Keywords

AQL, acceptance quality limit, sequential sampling, lot-by-lot inspection, sampling procedures, attributes inspection, acceptance sampling, curtailment, switching rules, average sample number.

FAQ

Q: What is this standard?

A: ISO 2859-5:2005 is the part of the ISO 2859 series that specifies a system of sequential sampling plans indexed by acceptance quality limit (AQL) for lot‑by‑lot inspection.

Q: What does it cover?

A: It provides sequential (progressive) sampling schemes and rules for switching between reduced/normal/tightened inspection, curtailment provisions to limit inspection effort, and tables/annexes with the detailed plans and average sample-number information for application to continuing series of lots.

Q: Who typically uses it?

A: Quality managers, inspectors, procurement and acceptance bodies, and statisticians who need AQL‑based, statistically defensible lot acceptance procedures that minimize average inspection effort—especially when product quality is very high.

Q: Is it current or superseded?

A: As published by ISO in June 2005 (Edition 1) the document remains an International Standard; ISO records show it as published and subject to the normal ISO review cycle for standards (periodic systematic review). Users should check with their national standards body or ISO for the most recent status or any revision activities before relying on the text for regulatory or contract purposes.

Q: Is it part of a series?

A: Yes — ISO 2859-5 is one part of the ISO 2859 series of standards on sampling procedures for inspection by attributes; other parts address single sampling plans, isolated-lot plans, skip-lot procedures, series introduction and related variable-sampling standards.

Q: What are the key keywords?

A: AQL, sequential sampling, sampling plans, attributes inspection, lot-by-lot inspection, acceptance sampling, curtailment, switching rules.