ISO 2859-1 focuses on sampling schemes for a lot-by-lot inspection with lots indexed by the acceptance quality limit (AQL). It is part of the ISO 2859 “Sampling procedures for inspection by attributes” series of standards. These sampling procedures help you decide on the product quality of an entire lot based on a good/bad inspection. Do you know the respective sampling plans?

1. Customer and supplier agree on a single sampling plan (n-Ac) = (80-1) according to ISO 2859-1. The customer detects two defective parts in the sample. What is he supposed to do?

• Draw a second sample
• Start to perform 100% inspections from now on
• Reject the lot

2. You use an operating characteristic curve (OC) to describe a sampling scheme. Which type of information does it contain?

• It indicates the percentage of lots which may be expected to be accepted for a given quality level.
• It contains nothing but the probability of acceptance for the acceptance quality level.
• A written instruction to conduct an inspection

3. Customer and supplier agree on a lot size of 1000 parts, inspection level II, AQL = 0.4 and a normal inspection for an incoming-goods inspection. What is the single sampling plan according to ISO 2859-1?

• (n-Ac) = (80-1)
• (n-Ac) = (125-1)
• (n-Ac) = (200-1)

Our Q-QUIZ is published once a month. You can find the answer to all questions of the current quiz online in the PDF file below.
This quiz was originally published in the December issue 2015 of the German magazine QZ Qualität und Zuverlässigkeit http://www.qz-online.de/service/preisraetsel.