ANSI/ASQ Z1.4-2008: Sampling Procedures and Tables for Inspection by Attributes is an acceptance sampling system to be used with switching rules on a continuing stream of lots for Acceptance Quality Limit (AQL) specified. It provides tightened, normal, and reduced plans to be applied for attributes inspection for percent nonconforming or nonconformities per 100 units.

This article introduces the different AQL inspection levels available to buyers. Those levels are mentioned in the ISO 2859-1 standard or its  equivalent, ANSI/ASQC Z1.4

ISO 2859-1 / ANSI/ASQC Z1.4?

In more than 95% of cases, quality inspectors who are performing random sampling AQL inspections are following a standard that guides them:ISO 2859-1 /ANSI/ASQC Z1.4:sampling procedures for inspection by attibutes, Sampling schemes indexed by acceptance quality limit AQL or lot-by-lot inspection

The standard helps the inspector know:

1)The number of products that should be taken out as a sample and inspected, based on the inspection level you mandated.

2)The AQL (acceptance quality limits) that dictate what percentage of products are permitted to ‘fail’ the inspection before the whole batch is classified as a failure.

The inspector can simply use the ISO 2859-1 master tables, commonly called AQL tables to calculate the sample size and the AQL limits based on the inspection level chosen. That level should be appropriate to the situation and products (for instance, a higher or special inspection level will be applicable for cases where you have more or fewer suspicions or tolerance of quality issues – more on this later…).

Table 1 which is used to get the code letter (to be used in table 2) based on your inspection level.

Table 2 which shows:

1)The number of samples to pick, based on the code letter;

2)The AQL limits based on the sample size from table 1 (the AQL is shown as a percentage, and then as acceptance & rejection amounts in numbers) where the inspector will know which AQL limits you have set, such as 1.5%, 2.5%, or 4.0%:

Pre-shipment inspections are a most effective inspection that confirms the whole shipment’s quality level. It normally requires the production to be 100% complete and at least 80% of goods to be packed into cartons. The checked samples are randomly selected according to AQL standard.

What’s Novas QC covered in this Inspection?

General on-site checking for Pre-shipment inspections includes the following criteria.

Quantity status

Product appearance

Performance, safety & function tests

Workmanship

Assembly

Accessories

Material

Colors

Logo & Labeling

Size & Measurements

Weight

Assortment

Carton status

Barcode scan test

Packing

Marking

Shipping Marks

Factory View

Product safety test

Besides the above, we can carry out a customized inspection according to your criteria.

Novas QC: Top Quality Assurance

Our professional inspections and detailed clear report formats will give you all the information that you need to make a final shipping decision