Frequently Asked Questions

The defetcs are classified within 3 categories, "Minor", "Major" and "Critical".
-Minor defects:
A defect that is not likely to reduce the usability of the product, but is likely to reduce the salability or a discrepancy from the defined quality standard or not same as the original sample.Minor defects are usually small, in most cases the customer wouldn’t even notice a minor defect on a product.
-Major defects:
A defect that is likely to result in product failure, reduction the usability of the product and obvious appearance defect affecting the salability of the product. A product with a major defect departs significantly from the buyer’s product specifications. Major defects are those which could adversely affect the function, performance or appearance of a product.
-Critical defects:
A defect that fails to meet mandatory regulations and / or affects the safety of the consumer when using the product. Critical defects render an item completely unusable and/or could cause harm to the user.These defects put businesses at serious risk of product liability issues and product recalls.

This is a Specific Plan that indicates the Sampling sizes to be drawn for Inspections and it is also associated with acceptance or non acceptance criteria in it.

AQL means “Acceptable Quality Level”, it illustrates the acceptable quality level of products needed.The designed value of defects is expressed as a percentage by the particular sampling procedure.Different AQLs may be designed for different classifications such as Critical, Major and Minor defect.

AQL 2.5 denotes that the permissible threshold for major defective goods is 2.5% of the total order quantity. If the batch produced contains a defect level that surpasses 2.5% defects, the product's quality does not meet the agreed-upon standards.

AQL sampling, which stands for "Acceptable Quality Level" sampling, is a widely used method to inspect and determine the quality of a batch of products. It involves randomly selecting a sample from the batch and inspecting it according to a predefined set of criteria. The results of the inspection help determine whether the batch meets the acceptable quality level or not. Here are steps on how to perform AQL sampling:

Step 1: Define AQL Levels and Inspection Criteria
Step 2: Determine Sample Size and Acceptance Number
Step 3: Randomly Select the Sample
Step 4: Inspect the Sample
Step 5: Count and Record Defects
Step 6: Compare Results with AQL Criteria & decide on next steps

AQL (Acceptable Quality Level) levels are used in quality control and sampling procedures to determine the maximum number of defects that are considered acceptable in a batch of products. The AQL level is denoted by a numerical value followed by a designation of I, II, or III representing different inspection stringencies. Each level has its own corresponding acceptable quality levels for critical, major, and minor defects.
Here are the typical AQL levels and their corresponding defect acceptance rates:
AQL Level I (AQL 1.0):
Critical Defects: 0
Major Defects: 2.5%
Minor Defects: 4.0%
AQL Level II (AQL 2.5):
Critical Defects: 0
Major Defects: 4.0%Minor Defects: 6.5%
AQL Level III (AQL 4.0):
Critical Defects: 0
Major Defects: 6.5%
Minor Defects: 10.0%

There are two main types of AQL used in quality control:
General Inspection Level AQL
Special Inspection Level AQL

An AQL of 1.5 means that the acceptable quality level for the production batch is 1.5%. In other words, no more than 1.5% of the total items in the batch are allowed to be defective

The AQL table is a valuable tool used in quality control to determine the sample size and acceptance criteria for inspecting a batch of products. It helps ensure that the batch meets the acceptable quality level (AQL) as defined for the specific product.

To read AQL Chart or Table -

• Identify the AQL Level and lot size range
• Find the Sample Size Code Letter & determine its size
• Perform inspection and compare the results 
• Decide on Lot Acceptance

The AQL inspection allows organizations to make informed decisions about accepting or rejecting a production batch based on the level of defects found in the sample.