Type Ii Error
Meaning ~ Probability of accepting an incoming shipment of manufactured goods that exceeds the maximum allowable defect rate, exposing the buyer to assembly line failures.
Defect Escape
Meaning
Quality failures occur when nonconforming items pass through factory inspections and reach the assembly line or the final buyer. Analyzing this defect escape allows managers to identify gaps in the quality control system. It does not measure the total number of defective parts produced, only those that were not caught.
Operational Vulnerability
Sampling plans sometimes miss bad units because the inspection did not cover the entire batch. A frequent defect escape can point to tired inspectors or inadequate lighting on the packaging line. Correcting this requires updating the testing protocols to focus on known failure points.
Preventive Strategy
Automated optical systems can reduce the human errors that occur during long sorting shifts. Reducing the chance of defect escape involves the use of sequential inspection gates at critical production steps. These gates catch errors closer to the point of origin, where rework is cheaper, which reduces the total waste generated during the production cycle.
Commercial Consequence
Sending defective goods to a customer leads to warranty claims, returns, and potential contract termination. When a defect escape occurs, the buyer often demands a complete audit of the supplier inspection process. The financial damage of these escapes usually exceeds the cost of installing better factory testing equipment.