Defect Classification and Root Cause Analysis in Apparel Production
Quality improves only when defects are counted, classified and traced back to a cause rather than reworked and forgotten.
The following sections cover the definition, the specification values, production control, testing and commercial impact.
Classifying defects
Grouping by type, such as sewing, measurement, fabric and trimming, makes patterns visible.
Well-handled, this becomes a selling point that customers can actually perceive rather than a technical footnote.
Pareto analysis
A small number of defect types usually causes most of the loss, so focus effort where the volume is.
Fix the limits for the whole size range, not only for the middle size, as grading changes the numbers involved.
- Request test reports on production fabric, not on development samples
- Verify the sampling plan and the number of specimens
- Store reports with roll or lot identification for traceability
Root cause techniques
Five-why questioning, fishbone diagrams and data review move from symptom to cause in a structured way.
Keep a physical standard at the machine so operators compare against the approved sample rather than memory.
Corrective and preventive action
Actions must be assigned, dated and verified, otherwise the same defect returns next season.
Test at least three pieces per lot, because a single sample can easily fall on the good side of the average.
- Agree tolerances in writing before the first sample is made
- Define the measurement condition and the direction measured
- Review the limit each season against real performance data
Measurement of improvement
Track defect rate per hundred pieces and rework hours to confirm that actions actually worked.
Choose suppliers who understand the requirement, because competence reduces the hidden cost of rework.
Summary
The technical content is straightforward. The discipline lies in writing it down, testing it on production fabric and repeating the result on the next order.
