AQL (Acceptable Quality Limit)

Definition

AQL (Acceptable Quality Limit) represents the maximum defect rate that is acceptable in sampling inspection. Since 100% inspection is impractical in manufacturing, a statistically reasonable sample is extracted for inspection, and if it passes this criterion, the entire lot is accepted. For example, AQL 1.0% means that approximately 1 defect per 100 units is acceptable.

Application in Manufacturing

Sampling Inspection Planning

• Determining lot size and sample size: The number of samples to inspect is determined by the AQL level
• Accept/Reject criteria: A lot passes if the number of defects found in the sample is below the allowable number
• Inspection level adjustment: Select from normal, tightened, or reduced inspection to control quality management intensity

Supply Chain Quality Management

AQL is applied differentially based on product characteristics and criticality. Critical defects are set at AQL 0%, Major defects at AQL 1.5%, and Minor defects at AQL 4.0%.

Manufacturing AI Application

Automated Defect Detection System

• Vision AI: Replaces visual inspection enabling 100% inspection with automatic AQL-based judgment
• Defect pattern learning: Learns defect types from historical data to improve detection accuracy
• Real-time AQL monitoring: Tracks defect rates in real-time on production lines and generates alerts

Predictive Quality Control

AI models analyze process data to predict potential AQL violations in advance and recommend process parameter adjustments for proactive defect rate control.

Key Points

• AQL does not mean zero defects - it represents an economically reasonable quality level
• Differentiate AQL levels based on product characteristics and customer requirements
• AI vision inspection enables transition from traditional sampling to 100% inspection