For every product manufactured, whether in batches or not, there is always a need to inspect them, as to whether or not the manufacturers meet the standards set for the product. Most manufacturers mass produce in batches. It would be a big waste of time, money and energy to go through all products one after the other. In fact, it might even be impossible to do so. That is why the AQL was introduced.
The AQL, acronym for Acceptance Quality Limit or Acceptance Quality Levels in some quarters, is an international standard for the ascertainment of quality in any product being inspected. 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.
Although the AQL is an internationally recognized standard of ensuring the quality of products, different countries, and importers set different levels of acceptable quality for minor, major and critical defects in a batch of products. This is because, different products require different AQLs, with respect to their means of production as well as other factors to be considered while varying the AQL. What are these factors manufacturers should consider while setting AQLs for their products?
Is it really necessary to set a suitable AQL for your production? Yes of course. Setting the right AQL for your production cannot be overemphasized. It helps you check and ensures the maintenance of the quality level of your products. Perfection is an abstract concept, especially in the line of production and manufacturing. Therefore, it is not expected that a manufacturer will deliver the good that is 100% without any form of defective. It is thus the job of the AQL to control the number of defective units in every batch produced.
1. How To Set a Suitable AQL Balance Between Acceptance And Refusal of Your Batch?
As stated on the onset, AQLs are international standards for ensuring the quality of products from any manufacturer’s production line. The AQLs, however, vary from product to product. There are various factors that can cause this variation in AQL across products. These factors are what every manufacturer should consider in setting suitable AQLs for their production.
First of all, in choosing a suitable AQL for your production, you as a manufacturer have to determine your level of tolerance. When this has been determined and understood, it becomes easier to set the AQL. Tolerance levels of products are usually set and determined in the following manner: Categorize The Defect Levels For Your Production
2. There are 3 categories for every form of production. Namely, Critical, Major and Minor Defects.
A production batch or a unit thereof that is categorized as having a critical defect is one that is totally unacceptable by any standards and are subject to outright rejection. Products in this category have to fail to comply with the basic standards required of such a product. That is to say that, regulations laid down to control the quality of the product has been disregarded. A fine example is an electric bulb that smokes out each time it is connected to electricity. This product is dangerous and therefore has a 0% rating.
Products deemed to have major defects are those that might not be considered acceptable by the consumer, not necessarily because they failed to respect regulations controlling their quality, but because of the condition, they are in at the time of production. One of such products may be a batch of vehicles that includes cars with poor body spraying. This does not make it unacceptable but will go a long way in reducing the value of the car. Products in This category are usually rated at 2.5%.
A product that deviates slightly from its specifications is regarded as one with minor defects. Usually, the end consumer may not mind the deviation, so, it may not really matter, like an electrical appliance with one or two missing screws but the product still works just fine. This will earn a rating of 4.0%.
Every production has one or two defective units. That is, not every unit produced in a batch, meets up to the standard of quality set by the manufacturer. In order to adequately control the quality, it is imperative to classify the various levels of defect On Your products. When this is done, it will aid you in setting the suitable AQL Level For your production line.
3. Factors To Consider While Setting Your AQL Limit
Choosing the proper AQL Limit for your product is very critical. You, however, have to consider the following factors.
If your products have an international scope and usage, you will have to adjust your AQL according to the market your products are going to sell. The point, therefore, is this, the Acceptance Quality Levels for every product varies from place to place and from market to market. If you are going to sell in markets in North America or Europe, the tolerance standard for critical, major and minor defects are 0%, 2.5%, and 4.0% respectively. Having a sound knowledge of this will help you to properly set the AQLs for your products. Armed with this, the manufacturer will be able to adjust his AQL to be milder or more severe.
The sensitivity of The Product
Products such as airplanes, drugs, and other edibles and consumables cannot afford to have a high defective rate. This is because the slightest derailment from quality standards set could have very dire circumstances, such as even loss of life. Therefore, it is imperative for manufacturers of products with this much sensitivity to be less tolerant of defects in their products. It is common practice nonetheless in these fields of industry manufacturing sensitive products, to have tools to ensure the reduction of defects in their manufacturing processes. It is hence not out of place to see this kind of products with 1% or less defect rate.
The manufacturer also understanding the preferences of his end consumers will also be instrumental to him choosing his acceptance quality levels in a way and manner that it tallies with his consumer’s preferences. If the manufacturer knows what exactly his consumers want, he would know precisely the standard of quality expected of his product, and will, therefore, according adjust his AQL Level.
There is no hard and fast rule in the choosing of AQLs for your products. As a manufacturer, you just have to understand your products, the market you want to sell it and the end consumer of your products. The decision of defect tolerance lies with you. If you decide that the defect tolerance for the whole batch of your products should not be beyond 1.5%, then that is your AQL.
It is very important therefore for every manufacturer to know that it is a very competitive market out there and therefore there is a need to suitably choose their AQL. The need for an expert to help you prepare AQL for your product is as important choosing the AQL itself. Terra inspection, with several years of experience in providing quality control services to manufacturers and the products. Tetra Inspection Management is committed to ensuring that your products meet all internationally recognized standard of quality; they will help you choose the most suitable AQL for your production.