What is Acceptable Quality Level (AQL)? Learn right now

What Is Acceptable Quality Level (AQL)?

Acceptable Quality Level (AQL) is a measure that applies to products and is defined in ISO 2859-1 as “the level of quality that is worst tolerated.” Acceptable Quality Level (AQL) tells you how many bad (defective) components are considered acceptable during random sampling quality inspection. It is usually expressed as a percentage or proportion of the number of defects compared to the total quantity.

Key Points:

  • The Acceptable Quality Level (AQL) is the worst tolerated quality level for a product.
  • Acceptable Quality Level (AQL) is different from product to product. Products that may pose a greater risk to health will have a lower Acceptable Quality Level (AQL).
  • Among products that do not meet Acceptable Quality Level (AQL), they are generally rejected on the basis of a percentage measurement tested during pre-shipment inspection.

How Acceptable Quality Level (AQL) Works?

The goods in the sample are randomly tested, and if the number of defective items is less than the default amount, the product is said to meet the Acceptable Quality Level (AQL). If the equipment does not reach the standard level acceptable for sampling (AQL), the manufacturers will review the various parameters in the production process to determine the areas that are causing the defects.

The Acceptable Quality Level (AQL) of one product may differ from one industry to another. Medical products, for example, have strict Acceptable Quality Level (AQL) because defective products are a health hazard (risk).

For example, consider a 1% Acceptable Quality Level (AQL) on a production run. This percentage indicates that no more than 1% of the batch may be defective. If the production run consists of 1,000 products, then only 10 products can go bad. If there are 11 defective products, the whole batch will be discarded. This statistic of 11 or more defective products is known as Rejection Quality Level (RQL).

AQL is an important statistic for companies looking for a six sigma level of quality control, a quality control method that Motorola, Inc. acquired in 1986. Acceptable Quality Level (AQL) is also known as Acceptable Quality Limit.

Special Considerations:

The Acceptable Quality Level (AQL) of one product may differ from one industry to another. For example, medical products are more likely to have a strict AQL because defective products can pose health risks.

In contrast, potentially malfunctioning products with benign side effects may have less severe Acceptable Quality Level (AQL), such as a remote control for a TV. Companies have to weigh the additional costs associated with rigorous testing and potentially more defect due to lower error acceptance along with the potential cost of returning a product.

Customers will definitely prefer zero defect products or services. Ideal Acceptable Quality Level (AQL). However, sellers and customers generally try to arrive at the business, financial, and security concerns and reach acceptable quality limits

AQL Defects

Examples of failures to meet customer quality requirements are called defects. In practice, there are three types of defects:

Critical Errors: Errors, when accepted, can harm consumers. Such defects are unacceptable. Major errors are described as 0% Acceptable Quality Level (AQL).
Major Defects: Errors are generally not acceptable to end-users, as they can lead to failure. AQL is 2.5% for major errors.
Minor Defects:
Defects are not likely to materially reduce product use for its intended purpose but differ from specific standards. Some end-users will still buy such products. Acceptable Quality Level (AQL) is 4% for minor errors.

AQL in Practice:

Acceptable quality level (AQL): AQL is generally considered to be the worst quality level which is still considered satisfactory. This is the maximum percentage of defects that can be considered satisfactory. Acceptable Quality Level (AQL) lot should be more likely to be accepted. A probability of 0.95 translates to a risk of 0.05.

Rejectable quality level (RQL): This is considered a level of unsatisfactory quality and is sometimes called Lot Tolerance Percent Defective (LTPD). Consumer risk is standardized as 0.1 in some tables. Rejection quality level (RQL) lot is less likely to be accepted.