GB/T 6378.7-2024 Active National standards

GB/T 6378.7-2024 Sampling procedures for inspection by variables—Part 7:Procedures for assessment of declared quality levels for percent nonconforming

Publish Date: 2024-09-29 Implement Date: 2025-04-01 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

Basic Information

Standard Code: GB/T 6378.7-2024

Standard Type: National standards

Standard Status: Active

is_force_gb: no

CCS Name: Mathematics

ICS Name: The application of statistical methods

Publish Date: 2024-09-29

Implement Date: 2025-04-01

Pages: 32 pages

Scope

The sampling plans and evaluation procedures specified in this document are used to assess whether the quality level of a population (batch or process, etc.) meets a certain claimed quality level. When designing these sampling plans, consideration is given to making their operating characteristic curves as closely matched as possible to the corresponding operating characteristic curves of the counting sampling plans in GB/T 2828.4, so that when the actual quality level of the population is inferior to the claimed quality level, the choice between counting sampling and measurement sampling is not affected by the acceptance probability. The sampling plans designed in this document classify a qualified population as unqualified with a risk of 1.4% to 8.2%; when the actual quality level is LQR (Limit Quality Ratio) times the claimed quality level (see Chapter 4), the risk of declaring the verification successful is 10%. For the cases where the process standard deviation is known and unknown, this document provides three sampling plans with different discrimination levels. Unlike the procedures in other parts of GB/T 6378, the procedures in this document are not applicable to acceptance sampling of batches. Generally, the balance between the risk of making erroneous conclusions in acceptance sampling and verification sampling is different. This document is applicable to various forms of quality verification, that is, using the test results of samples to determine whether a verified population does not meet a certain claimed quality level. This document is applicable to situations where it is allowed to extract some units from the verified population to form a random sample. The sampling plans provided in this document can be used (but are not limited to) for inspecting the following products, for example: —-Final products; —-Parts and raw materials; —-Operations; —-Work-in-process products; —-Inventory products; —-Maintenance operations; —-Data or