Product Inspections are performed by randomly selecting samples from the whole consignment. Results are classified as defective or non-defective in accordance to your specified requirements and to a type sample.

SAMPLING OR INSPECTION LEVELS
There are several levels of inspections appropriate to the different stages of production. The level and the consignment size will determine the size of the sample to be randomly selected.

The levels used for the 3 pre-shipment inspections are as follows:

If a tighter inspection plan is needed for special cases where stricter controls are required, Level III may be applied. Level III generally means that a larger sample size will be checked, of which a smaller proportion is allowed to be defective.

Level S3 is a special level used in conjunction with Levels I, II and III. Level S3 is used for field tests and performance measurements where it would not be practical to perform such tests on larger sample sizes

DEFECT CLASSIFICATION
Defects detected during an inspection are classified within three categories “Critical”, “Major” and “Minor”. The normal definitions are:

Critical: Defects against safety requirements or that will result in hazardous or unsafe utilization.

Major: Functional defects or defects in the appearance of the product which will result in the failure of the product to perform or lessen the value/salability of the product.

Minor: Defects that are unlikely to affect the use of the product, but nevertheless may influence the sale or the level of returns.

ACCEPTABLE QUALITY LEVEL (AQL)
The number of Critical, Major and Minor defective units allowed are controlled by the Acceptable Quality Level (AQL)

AQL is a number that determines the maximum number of allowable defective units in a sample. AQLs can be considered as an statistical average. It is however, not a percentage. The AQL can also have an influence on the size of the sample for very small or very large consignments,.

Different AQLs may be designed for different defects such as critical, major and minor defects. The AQL should be agreed upon between the buyer and the supplier, prior to manufacture or delivery of the product.

The following AQLs are applied by QC Direct unless otherwise instructed by the client: