3 Defects Classification in AQL Product Inspection

What’s Defect Classification in AQL Inspection?

Kitchenware Inspection Poor coating defectHave you ever wondered why essential to define and classify your product quality defects in AQL Inspection? What’s AQL defect classification? Not knowing whether to categorize defects as “major” or “minor” can be quite challenging.

For these reasons, defect classification is a crucial step because it determines if the goods pass or fail the test. If the defects are minor, it means they don’t affect their salability. But if the products were set to distribute to a high-end retailer with almost zero tolerance to quality issues, then any defects available are considered “major.”

To help you make better decisions, we provide you with a complete guide on the types of defects. Quality control experts do categorize quality defects into three classifications:

  • Minor

  • Major

  • Critical

The severity and nature of the defect will determine the group it belongs to. Most of the importers do have the authority of specifying the number of every defect type they can accept in their finished items. It is this tolerance that will, in turn, determine the number of units per SKU the inspector will be checking.

Most importers set the quality tolerance level by use of an AQL table used in an acceptable quality level sampling method. (Related: How to use AQL Table?)

Minor Defects

In most cases, the minor defects will be the insignificant and small issues that don’t affect the form or function of any item. Most customers will never notice a minor defect on a product, and some customers will not return the product just because of their minor defect.

The importers set the highest tolerance level when it comes to the application of that standard to a smaller defect in the AQL sampling that has been inspected. However, a product can still fail inspection when the number of minor defects is beyond the set limit by tolerance.

(Related:3 different product inspection result in Third Party Inspection report)

Major Defects

Major Defects in AQL Defects classification_Dent mark

The major defects are much more serious than the minor defects. An item having a major defect will always depart from the product specification of the buyer. The major defects are those who are capable of affecting the appearance, performance, and function of an item.  Customers can easily notice these defects, and probably they will return the item, raise a complaint, or even seek a refund

A good number of importers have limits of major defects set lower than those of minor defects in the sample size that has been inspected. In most cases, they will accept a product with a few major defects, although they are most likely to reject the order or request the supplier to rework or hold onto it in case it fails inspection due to a high number of major defects.

Critical Defects

Critical Defects in AQL Defects classification_Nail on outside

They are the most serious type of defects and do render a product unusable or even capable of causing harm to someone near it. Critical defects can put the business at huge risk or product recalls lawsuits and liability issues. Most importers usually have a zero-tolerance policy on orders that have critical defects. Any product will automatically fail inspection when a critical defect is found.

Related: Recall list on CPSC.gov to understand the types of defects caused products recall.

Example of Different Type of Defects  in Different Products

There can be different quality defects on different items, depending on the standards, production processes, and materials. Here are some of the common examples of the three types of quality defects to better understand how is classification of defects.

  1. Softlines

The Softline items comprise of home textiles, raw fabric, garments footwear, and other knitted or woven pieces. For instance, the garments are prone to vulnerability, and it’s easy to end up with quality defects due to the labor-intensive process of production in their manufacturing. The human hands that take part in stitching and sewing do raise variability in production while the use of automated production processes like robotics in electronic assembly and injection molding in hardlines goods reduce variability.

Here are some of the most popular Softline defects

  • Minor defect: Untrimmed Thread ends, Blind stitching, Snarled stitches, Slight poor printing, fly yarn, pull out the loop, etc.

They are the popular quality issue available in garment manufacturing. However, it is possible for factories to rework the defect by cutting the extra threads. There are times when you can categorize the untrimmed threads as a major defect, depending on the type of customers you have.

  • Major Defect: The Missing Stitches, Loop stitches, Hole, Color shading, Broken stitches, Skipped stitches, Open seam, Malfunction accessory, etc.

They usually appear due to operator error of sewing machine fault. Missing stitches do have an impact on the product’s visual appearance, and it can easily affect the strength of the seam, making it a serious quality issue.

  • Critical Defect: Needle in an Item, any sharp point, mildew products, foreign insect, blood mark, etc.

There are times when the needles can be hazardous to the end-user in case they do end up with finished items. The quality issue is always considered to be a critical defect, and its presence can easily result in the product failing inspection.

  1. Hardlines

The hardline items comprise a wide range of products made from plastic, wood, or metal materials. The category consists of sporting equipment, tools, building materials, cookware, and furniture.

Here are some of the popular hardline defects:

  • Minor Defect: Light Abrasion on the surface, Dirt stain, Oil stain, 

We can relate a light abrasion found on the surface of a hardline item to rough handling or just a production process. Light abrasions, together with other damage to the product surface, will never hurt the scalability of a product.

  • Major Defect: Deeper scratch on the product logo, Broken, Crack, 

Repairing a scratch on a product logo is a bit difficult; hence is considered to be a major defect. They are never tolerated in larger numbers since they can easily affect the scalability of the product and brand-consumer perception.

  • Critical defect: burr or a sharp point on a product, Foreign hair, etc.

Burr or sharp points can easily cause harm to the user and are known to be among the popular causes of inspection failure.  Such hazards are identified to lead to items being recalled explaining why most importers consider them as critical defects.

  1. Electronic and Electrical Items

Electronic and Electrical Items comprises of household appliances, consumer electronics, and power tools, certain types of toys and products that need electricity to operate.

Here are some of the popular defects:

  • Minor Defects: Removable mark on a product, Flow mark, dirty mark, Rough surface, short scratches, poor printing, poor assembly, etc.

The marks found on the surface of a product can include excess glue or dirt. They are usually considered small since they can be wiped away or are easily removable.

  • Major Defect: Malfunction or Non-Function, Burr, Rusty, Button insensitive, Intermittent function, etc.

Some malfunction problems facing an electronic product can include turn-on failure, connectivity issues, or display issues. Depending on the product’s complexity, the rework of hardware or software may be required to help in correcting the problem.

  • Critical Defect: Damaged Wiring, Earth terminal loosen, metal residue, Circuit short, earth continuity test failed.

Having a product that has a damaged wiring system where copper is exposed can easily endanger the product and users’ live. Such damage does create a possibility of electric shock, risk of fire, or electrocution.

  1. Industrial Components

The industrial components refer to a broad term that can comprise conduit piping, wind turbines, fabricated steel, maritime equipment, gas valves, and other materials or machinery which have been designed to be used for industrial purposes.

Here are some of the common defects that can occur in industrial products:

  • Minor defect: Surface imperfections

Having a surface imperfection such as a welding protrusion in a steel pipe will never affect the functionality or use of the product. However, it is important for one to consider the imperfection type and the intended use of the product before you consider the defect to be minor.

  • Major Defect: Out of Tolerance non-critical dimensions

Having minor deviances in measurements and weights can be undesirable in any finished product. Still, in most cases, it will never have an impact on the overall function of an industrial item. One can consider the dimensional deviations dangerous when they do affect the purpose of a product, production processes, or performance.

  • Critical Defect: Rust

Experiencing corrosion before shipping can be an accelerated degradation or product failure sign. Rust should be considered to be a very serious issue, especially when you are importing water pipes or gas.

Defect Classification in Inspection Checklist

A quality control expert is in a position of suggesting the right tolerance for defects that are known for your item. However, it is up to the buyer to indicate their tolerance for every quality defect type.

In most cases, the importers will always have all their defect classification and tolerance listed in a quality control document. The inspection checklist will comprise of information such as the onsite testing procedures, packaging requirements, and right inspection equipment. The document will also comprise an extensive list of known and popular quality defects together with the type of product.

At times it can be impossible to account for every quality defect. However, the more complete the list of defects you offer, the higher the chances your supplier will abide by the tolerances. The quality control inspector you hire will most likely use the same standard when carrying out an inspection of your products against the inspection checklist.

Addressing the Quality Defects of Your Items

It is important that you identify the quality defect in your order before you shipping to help in ensuring that customers’ expectations have been met. Contracting third party inspection companies to carry out inspection of your order and report the types and numbers of defects available will be time-saving and of great efficiency. The report they compile will reveal the defect numbers in comparison to the number of defects that are allowed depending on your tolerance.

Here are some of the important things you can consider doing to help address defects found in the order.

  • Consider requesting the supplier to correct the quality issues by either reworking on the product or replacement of goods.
  • Always reinspect to ensure that all the defects are corrected and removed.
  • You can decide to chargeback the supplier for any quality issues or inspections.
  • Destroy all the goods that can’t be sold to help in preventing them from getting to the customers.


We do have guidelines which quality control experts are supposed to follow to help classify a defect. However, the buyer will always consider the rate of various types of defects and the effect they can have on their customers.

Author: AQI Service as a professional quality control service company in China specialized in providing a complete range of quality inspection and testing certification services in China & Asia for global importers, buyers, retailers, and sellers.

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