End-line and final inspection improvement

Learning objectives

• Assess end-line/final inspection performance with escape and false-reject rates.
• Use attribute agreement to calibrate inspectors against a shared standard.
• Redesign inspection as risk-based, not layered.

Problem and CTQ

Inspection can miss defects, create delay or give inconsistent disposition. Manage escape rate, false-reject rate and buyer AQL together, not one at a time.

DMAIC path

• Map end-line, final, repair and re-inspection flows.
• Validate attribute agreement (kappa) against a calibrated defect library.
• Stratify escape and false-reject rates by lot, buyer, style and inspector.

Improvement choices

• Calibrated defect library and inspector certification.
• Risk-based allocation of inspection minutes.
• Ergonomic station, lighting standard and digital traceability.

Control plan

• Escape rate, false reject, agreement/kappa, final pass, inspection minutes, repair loop time and lot rejection.
• Buyer/quality authority sign-off for any AQL or acceptance change.

Garment-factory example

A women's woven blouse programme shows kappa 0.42 between two inspectors on 'puckering'. A photo-based defect library and joint calibration raise kappa to 0.81 while escape rate falls from 0.9% to 0.3%.

Common mistakes

• Treating inspection as prevention.
• Changing AQL informally to hit a shipment date.