Question 1

What AQL level should I use?

Accepted Answer

AQL 0.065-0.15% is used for critical defects (safety hazards). AQL 0.40-1.0% is typical for major defects (functional failures). AQL 1.5-4.0% is common for minor defects (cosmetic issues). The appropriate level depends on the consequences of defects reaching the customer and industry standards.

Question 2

Does passing AQL inspection guarantee lot quality?

Accepted Answer

No. AQL sampling is a probabilistic method — it reduces risk but cannot guarantee zero defects. A lot at exactly the AQL defect rate has roughly a 95% chance of acceptance. Lots with higher defect rates have lower acceptance probability. For zero-defect requirements, 100% inspection or process capability control (Cpk) is necessary.