What is AQL (Acceptable Quality Level)?
When you place an order for a large batch of T-shirts, inspecting every single piece may not be practical. AQL allows you to inspect a small, random sample, giving you the confidence that the entire shipment meets quality standards. It sets a clear threshold for how many defective items are acceptable in the sample before rejecting the entire lot.
Why Use AQL?
Saves Time & Money: No need to inspect 100% of the items—just a representative sample.
Sets Clear Expectations: Both buyer and factory agree on acceptable defect limits before production.
Balances Quality & Cost: Stricter AQLs mean more costly inspections; looser AQLs allow faster delivery times.
How AQL Works: Step-by-Step
Classify Defects
Critical Defects: Safety or compliance failures (e.g., missing fire-safety label)—zero tolerance.
Major Defects: Significant issues that impact the appearance or function (e.g., large stains, broken zippers).
Minor Defects: Small flaws that don’t affect the garment’s wearability (e.g., loose threads).
Pick Your AQL Levels
Common thresholds: 0.65, 1.0, 2.5, 4.0, 6.5
0.65–1.0: High-end or safety-critical items
2.5–4.0: Everyday apparel
6.5: Basic trims or bulk orders
Determine Sample Size
Use the ANSI/ASQ Z1.4 or ISO 2859-1 tables to calculate the appropriate sample size based on your batch size and inspection level.Inspect & Count
Examine the garments in your sample, and tally critical, major, and minor defects.Compare to Acceptance Numbers
The table provides:Ac (Accept): Maximum defects allowed
Re (Reject): Number of defects that trigger rejection
If the defect count is under Ac for all categories, the batch passes. If any category exceeds Re, corrective action is required.
A Quick Example
Order Size: 2,500 T-shirts
Inspection Level: II (general)
Sample Size: 200 shirts
AQLs Chosen: Critical 0.65, Major 2.5, Minor 4.0
Acceptance Numbers: Critical 0, Major 10, Minor 14
After inspecting 200 shirts, you find 8 major defects and 12 minor defects—both below the limits—so the batch passes.
AQL is a powerful and cost-effective way to maintain high-quality standards while managing inspection costs. By defining defect categories, sample sizes, and defect limits upfront, AQL provides a clear, agreed-upon framework for quality control, allowing manufacturers to conduct efficient, objective inspections. This system helps reduce defects, keeps production costs down, and minimizes the risk of customer complaints, ensuring that only high-quality products reach the market.
By using AQL, you ensure that your production runs smoothly, your customers stay satisfied, and your brand reputation remains strong. It’s a win-win for everyone involved in the manufacturing process.
