Quality formula
The share of inspected units that have at least one defect. Each unit is counted once, however many defects it has.
Defective % = defective units / units inspected × 100
| Symbol | Meaning | Unit |
|---|---|---|
| U_d | Units with one or more defects | pcs |
| U | Units inspected | pcs |
Use it alongside DHU, and in AQL inspection where the lot decision is based on defective units.
Out of 125 garments sampled, 6 have at least one major defect.
Defective % = 6 / 125 × 100 = 4.8%
DHU counts defects per hundred garments checked. The formula, how it differs from defective percentage, a worked example from end-of-line checking, and how to turn DHU data into action on the line.
AQL sampling decides how many garments to inspect from a lot and how many defects are allowed. How the sampling tables work, inspection levels, code letters, accept and reject numbers, and what AQL does and does not guarantee.