To ensure the quality of a batch of products, many companies use AQL quality sampling. In this article, we explain what this type of sampling consists of and how the Mapex platform helps you to implement it.
Poor quality management can lead any industrial company to disaster in economic and reputational terms. That is why, in an increasingly competitive market, it is essential to make use of different methods in order to achieve zero-defect manufacturing.
In this context, the application of statistical techniques has become one of the great allies of industrial companies when it comes to measuring, controlling and mitigating the most common risks associated with non-quality. They make it possible to combine exhaustive control of processes with a reasonable cost of quality.
Below, we focus on the Acceptable Quality Limit (AQL), an internationally recognized sampling methodology used by organizations in all kinds of industrial sectors.
What is AQL?
ISO 2859-1 defines AQL as “the worst quality level that is tolerable for a product”. In other words, it is a clear limit, expressed in the form of numerical data, that allows a decision to be made without any doubt as to the acceptance or rejection of a given batch of raw material or product.
Each company determines its own quality tolerance levels, which may vary, for example, according to internal criteria (risk acceptance, best practices, etc.) or external criteria (standards and regulations associated with the industry to which the company belongs).
In fact, depending on the degree of stringency that the organization has agreed with its suppliers or customers for each type of product, a single critical defect can lead to the rejection of an entire batch.
How AQL tables work
Broadly speaking, AQL tables help companies to determine, on the one hand, the inspection levels (or sample size to be analyzed) and, on the other hand, the acceptance levels (considering that defects can be minor, major or critical).
Once the sample has been analyzed, if the percentage of units that do not comply with the quality standards is lower than the AQL agreed by the company, that batch of products is considered valid. If the opposite situation occurs, the company can proceed to reject the goods.
Likewise, results that are very close to the AQL limits are also very useful for many companies, as they allow them to review with their suppliers or customers possible continuous improvement actions in order to never exceed these levels.

How does Mapex help you implement AQL?
An MES system can make a difference when it comes to implementing and automating AQL in the manufacturing processes of your industrial company.
The Quality module of the Mapex platform already incorporates AQL tables. This is a very useful feature for inspecting both the quality of a batch of raw materials or components that are received from a supplier and the goods that are shipped to customers who work with this standard.
In addition, thanks to the Mapex MES solution, which captures and collects data from the quality area in real time and 100% reliably, companies can also automate the implementation of an action plan if the overall result of the inspection is NOK: reject the lot, reprocess it, hold it pending further information, perform new sampling with stricter AQL criteria, etc.
Finally, apart from the daily operations, the Mapex Quality module automatically generates a historical report with a summary of the AQL results. This document can be very useful to demonstrate to the customer that the batches shipped comply with the quality standard.
For more information on this and other features of the Mapex MES system, please contact our team.