existinspection of goodsIn the report."Achilles' heel,major flaw,minor flaw" is based on the extent to which a product defect affects the safety of use, product functionality, appearance and customer acceptance, with the following meanings:
I. Fatal flaws: "red herrings" that threaten security
Critical Defect refers to defects that may cause harm to the user's personal safety, or seriously violate relevant laws and regulations, industry mandatory standards. These defects can directly cause the product to lose its basic value of use, and there is a great safety risk. For example, electrical products with short circuit wiring that may cause fire or risk of electric shock, and food products that contain toxic and hazardous substances are all fatal defects. Once a fatal defect is found, the product is usually judged to be unqualified and is not allowed to leave the factory for sale.

II. Major deficiencies: "hard" impacts on functionality
Major Defect (Major Defect) is a defect that does not pose a threat to the safety of the user, but will seriously affect the main performance, use function or durability of the product, resulting in the product not being able to be used normally or significantly reducing its use value. This type of defect will make the product unable to fulfill the core needs of customers. For example, a cell phone that does not make normal calls, an air fryer that does not start properly, or a garment that has visible open threads and affects wearability are all considered major defects. Products with major defects are also generally difficult for customers to accept and require rework and repair or downgrading.
III. Secondary defects: "Defects" that do not affect use
Minor Defects (Minor Defect) refers to those defects that have no effect on the main performance and use function of the product, but only some slight defects in appearance and workmanship, which will not affect the normal use of the product and will not reduce the core value of the product, but may have a certain impact on the aesthetics of the product or the customer's psychological feeling. For example, minor scratches on the surface of the product but not obvious, threads on the garment are not trimmed cleanly, and the position of the product label is slightly shifted, all of which are minor defects. Products with minor defects can usually be shipped with certain treatment, although it may affect the selling price of the product or customer satisfaction.

Summary of key differences
| typology | Degree of impact | user response | business risk |
| Achilles' heel | Security/legal/loss of functionality | Returns, Complaints, Litigation | High (recall, compensation) |
| major flaw | Significant decline in functionality/appearance | Possible return | Medium (cost loss) |
| minor flaw | Minor blemishes | Tolerance or neglect | Low (long term impact on word of mouth) |
In short, the division of these three kinds of defects helps to clarify the severity of product quality problems, and provides a basis for subsequent product treatment, quality improvement and so on.
