Why Acceptance Quality Limit (AQL) is an Essential Part of Quality Control
If you’ve been planning to organize a product inspection, the term AQL will probably sound familiar. If not, then you need to know about it! AQL stands for Acceptance Quality Limit. It’s nothing new, but it’s an important sampling methodology used in quality control worldwide.
The Meaning Behind AQL
AQL is described in ISO 2859-1 as the quality level that is ‘the worst tolerable,’ meaning that it specifies the maximum acceptable number of defective units. Manufacturers tend to prefer having smaller samples checked, as inspecting entire batches is time-consuming and prohibitively expensive.
Inspectors adhere to established international guidelines and check for damage, defects, odor, color fading, label readability, functionality, and much more. The AQL sampling itself addresses two crucial issues.
The first is how many units to inspect in a specific shipment, and the second is how many defective products are acceptable before the inspection fails. The results are published in a report, enabling the client to make a fully informed decision on whether they should accept or reject the whole batch.
Your inspection report will detail all the results, along with images and relevant data points. It also clearly establishes whether a shipment has passed or failed the specified AQL. That’s why it’s so vital that you fully grasp AQL if you are serious about working effectively with inspectors.
Otherwise, there is a real possibility of misinterpreting the report, causing quality disasters. Many businesses use an AQL sampling chart or table to manage the process. You can find many detailed examples of these charts online, together with guidelines on how to navigate them.
The AQL chart features two tables, generally referred to as the ANSI/ASQ Z1.4 tables. You can use them in parallel to identify your sample size and establish the number of allowable defects per lot. These tables are derived from the work of Harold F. Dodge, who developed a quality control system for inspecting US military hardware at the Pentagon during World War II.
For most general consumer products, the typical AQL levels are 2.5% for major defects, 4.0% for minor defects, and 0% for critical defects. A shipment with just one critically defective unit will automatically fail an inspection.
Today, manufacturers use AQL to inspect a wide range of consumer products from furniture to appliances. At Shark Design we’re aware that the AQL chart in garment industry circles is highly valued. It’s an important aspect of our work, and we take care that our clients are fully informed on quality control methodologies.
We know how to work with inspectors to deliver the best quality product, but we also strive to make you part of the process. Nothing is left to chance.