Explaining AQL 2.5 for Quality Inspections - HQTS (2024)

AQL stands for Acceptance Quality Limit and is a term related to the maximum number of defects that buyers and suppliers have agreed on in a batch. Importers can set different AQLs, including: critical, major and minor defects.

When exporting goods, most Asian export companies are familiar with this term and particularly use AQL 2.5 forms in purchase orders and AQL inspections. But what does AQL 2.5 mean, and how is it calculated? In this short guide, we’ll go through everything you need to know about AQL 2.5 and teach you how to read an aql chart.

What Is AQL?

When importing goods from a supplier, it is important to ensure that certain levels of product quality are maintained and to have an efficient method for assuring those levels of quality.

AQL sampling is a practical and effective way to perform quality assurance whilst ordering manufactured goods, helping to reduce any risks before officially accepting the items.

Listen to the video below if you want to learn how AQL is used in quality control inspection and how you can determine the AQL sample size within an AQL table.

What Are The Types of AQL?

Within the AQL sampling method, there are generally three main AQL levels used, and these include:

  • Critical (0% defects)
  • Major (2.5% defects)
  • Minor (4.0% defects)

Critical defects (0%) are not acceptable at all, as the user could be harmed, major defects (2.5%) represent products being considered unacceptable by the end- user and minor defects (4%) fail to meet specifications in ways that most buyers would still accept.

Generally speaking, the level of accepted defective goods depends on the agreement between the supplier and the buyer, based on the level of risk they decide on. Products that pose more of a health risk will have a lower AQL threshold. Once an AQL Standard is agreed on, it will be used as a reference throughout the inspection process, determining the acceptable percentage for every defect in an order.

What Does 2.5 AQL Mean?

AQL 2.5 means the acceptable level of major defective goods is 2.5% of the total order quantity. If the batch produced contains a defect level that exceeds 2.5% defects, then the quality of the product is not living up to the agreement. The AQL 2.5 level is commonly used in the garment industry, Chinese manufacturers and more.

You can use the HQTS AQL Calculator for your quality inspection needs:

Order Quantity:

Inspection Level:

Critical Defects

Select AQL:

Sample Size:

200

Accept Point:

Reject Point:

Major Defects

Select AQL:

Sample Size:

200

Accept Point:

10

Reject Point:

11

Minor Defects

Select AQL:

Sample Size:

200

Accept Point:

14

Reject Point:

15

What Is an AQL Chart?

An AQL chart is a tool that can be used to determine the sample size for inspection purposes and the acceptable defective units. The AQL chart also offers more options, including inspection levels and standards for particular unique cases.

The most common standard is AQL Table 1. This is used as an important tool when carrying out quality control inspections, this AQL table simplifies the information for the buyer, the manufacturer and the quality control provider; as they can all come together and agree on set quality inspection standards.

How To Read an AQL Chart

Reading an AQL chart 2.5 is relatively straightforward.

The chart below displays a single sampling plan for when normal inspections are carried out, the check marks on the table show how many products have passed and the crosses show how many products failed. The up arrows determine the sampling size and if you see an arrow that equals or exceeds the batch size, you should complete a full inspection or a piece-by-piece inspection.

Explaining AQL 2.5 for Quality Inspections - HQTS (1)

Why Is AQL Important in Quality Inspections?

AQL is a vital tool when performing sampling inspections, inspection teams can use an AQL standard to ensure the number of units inspected in a given sample is correct and the number of defective units that could cause a failure result is noted down. The AQL Standard determines the required sample size that needs to be inspected and the number of rejected units.

Inspecting a large number of units at once can be too difficult for manufacturers and therefore, incorporating a method such as AQL 2.5 can be extremely helpful for businesses.

Hence, AQL is a preferable method when you need to efficiently check whether the products in the batch are up to the defined quality standard. However, if you are only purchasing products in small volumes, your business may have the resources to test everything at once. But as quantities rise, piece by piece inspections can become harder to manage due to time restraints and costs.

AQL 2.5 is a robust, useful model that has successfully been used over many years. However, it is important to note AQL inspections do not guarantee a defect-free experience, as minor defects may go undetected. But, AQL allows you to select the percentage of defects that you are willing to accept/risk and it’s a secure option when it comes to gaining valuable insight into your supply chain, your products and your business.

After completing an AQL Inspection, the agency will issue a shipment certificate and this will clarify whether you passed or failed. The inspector will conduct a pre-shipment inspection before production commences and issue the pre-shipment report, this will be attached to your documents when shipping.

Conclusion: What Is an Acceptance Quality Limit (AQL 2.5)?

AQL 2.5 sampling is a practical and effective way to perform quality assurance on an order of manufactured goods to reduce the risk prior to accepting an order. Do you need help calculating how many units should be inspected during an inspection, or find out the acceptable defect number? Use our free AQL Calculator!

At HQTS, we use the AQL sampling method in our inspection services and always thoroughly document the results of the inspection in an inspection report. Backed by the industry knowledge and experience of nearly 1,500 professionals, in more than 20 countries, HQTS is well-suited to be your partner in quality. Contact us here today for more information or any questions you may have.

Explaining AQL 2.5 for Quality Inspections - HQTS (2024)

FAQs

Explaining AQL 2.5 for Quality Inspections - HQTS? ›

AQL 2.5 means the acceptable level of major defective goods is 2.5% of the total order quantity. If the batch produced contains a defect level that exceeds 2.5% defects, then the quality of the product is not living up to the agreement.

What is an example of 2.5 AQL? ›

Assuming the AQL level is 2.5, the acceptance number is 5 and the rejection number is 6. In other words, the AQL suggests that you accept this batch of products if five or fewer defects are identified in the inspection, but to reject the batch if six or more defects are found.

How to interpret an AQL sampling plan? ›

To the right of the 'Sample size,' you'll see various columns representing different Acceptable Quality Levels. For most general consumer products, the standard AQL levels are 2.5% for major defects, 4.0% for minor defects, and 0% for critical defects. That's why we've underlined '2.5' and '4.0' above.

How to define aql level? ›

The AQL is defined as the least tolerable quality level of a product. That is, the highest number of defective units of the product, of which anything above will lead to the rejection of the entire batch of the product.

What is the importance of AQL in quality control? ›

AQL plays a pivotal role in quality control by providing a statistical method for accepting or rejecting a batch of products based on the quality level. It aids in defining the criteria for acceptance, offering a way to objectively measure the acceptable quality level of products.

What does 2.5 AQL mean in inspection? ›

AQL 2.5 means the acceptable level of major defective goods is 2.5% of the total order quantity. If the batch produced contains a defect level that exceeds 2.5% defects, then the quality of the product is not living up to the agreement.

How to determine sample size for inspection? ›

Inspectors use the AQL tables to determine the correct sample size (in simple terms, how many samples are to be picked and inspected from the whole product quantity) and the acceptance level (in simple terms, how many samples can be defective).

What is the AQL summary? ›

The acceptable quality level (AQL) is a measure applied to products and defined in ISO 2859-1 as the “quality level that is the worst tolerable.” The AQL tells you how many defective components are considered acceptable during random sampling quality inspections.

How to calculate AQL manually? ›

AQL Sampling
  1. First select the appropriate industrial sampling plan.
  2. Determine the AQL %
  3. Decide the sampling plans parameters.
  4. Establish the sample size, accept and reject criteria.
  5. Randomly select the parts.
  6. Inspect each part for the given feature(s)
  7. Accept or Reject the remaining parts.

What is an acceptable defect rate? ›

The industry average AQL for minor defects is 4%. Major Defects - Not acceptable to the customers. Usage of the product will most likely result in failure. The industry average for AQL for major defects is 2.5%. Critical Defects - If accepted, this type of defect could potentially harm or injury the customer.

What is AQL sampling rules? ›

The AQL sample size of 125 units for inspection should be chosen randomly to guarantee the accuracy of the results. Apart from the AQL sampling table, you can also use the AQL chart. For AQL 2.5, only 7 defects are acceptable, while 8 defects or more are rejectable.

What is a good sample size for quality assurance? ›

A good maximum sample size is usually around 10% of the population, as long as this does not exceed 1000. For example, in a population of 5000, 10% would be 500. In a population of 200,000, 10% would be 20,000.

What is the AQL strategy? ›

AQL (Acceptable Quality Limit) Sampling is a method widely used to define a production order sample to determine if the entire product order has met the client's specifications. Based on the sampling data, AQL standard can help the customer can make an informed decision to accept or reject the lot.

What are the disadvantages of AQL? ›

AQL sampling often leads to activities that are associated with attempts to test quality into a product. AQL sampling can reject lots that are a result of common-cause process variability.

What is a critical defect in AQL? ›

However, some AQL numbers and definitions are often used as contract standards: Critical defects: This category of defects make a product either unusable or may put a user at risk of harm. Companies and importers generally set the AQL for critical defects at 0.0.

What is the special inspection level in AQL? ›

AQL Special inspection levels (S-1, S-2, S-3, S-4) are typically used for certain types of on-site inspections or checks that are only necessary on a relatively small number of units in the lot.

What is an example of AQL? ›

AQL Example 1

Company A orders 15,000 shirts from a clothing manufacturer in China. All shirts are produced in a single batch. Agreed-upon AQL levels are: 0.0% for critical defects, 2.5% for major defects, and 4.0% for minor defects. Inspection level is general inspection level II.

What is the standard for AQL Level 2? ›

Level II is the standard and is most commonly used. For example, if you are producing 8,000 items, at level II that results in the letter L which in turn corresponds to the inspection of 200 items in the second table. On the top of the second AQL chart, you can find the defect levels, ranging from 0 to 6.5.

How to calculate AQL percentage? ›

An AQL of 2.5 means that only 2.5% of an order can be defective in order for it to be acceptable. If more than 2.5% of the other is defective, then it doesn't meet the agreement between the buyer and producer. So for example, if 20,000 pairs of shorts are ordered, only 1,250 can be defective to reach an AQL of 2.5.

What does an AQL of 1.5 mean? ›

It is used mainly to detect the pinhole defects using a water weight test that assures people that they are protected from holes, weak areas, and rips. AQL of 1.5 represents that there are less than 1.5% of defects in a batch of gloves.

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