What is Defect? What is Alter? What is Defective Pieces? How these are measured?

Defects

Defects are the collection of non-conformances which are not accepted by the end-user of items. A defect is a parameter which decides that a garment is qualified or not. When the number of defects exceeds the acceptable quality level, the defective pieces will be rejected. When the defects are less in a garment it is considered as a good quality garment and if defects are high in a garment it is considered as the worst quality garment.

Alter or Alteration

The definition of alter or alteration exactly the same as defects. It sometimes used locally.

Defective Pieces

Defective pieces are those pieces, which are separated for alteration during checking may be for any causes.

Defective Pieces or Defected Garments are those items in which at least one defect has been found. One defective piece may contain one or more defects.

Measurement Procedure of DHU and Defective Pieces

For quantitative measurement of Defects and Defective Pieces, there is two popular measuring units. They are –

1. DHU (Defect Per Hundred Unit) and

2. Percent Defective.

1. DHU (Defect Per Hundred Unit)

DHU is the number of total defects found in 100 checked garments item. The formula to calculate DHU is-

DHU = (Total number defects found X 100) / Total pieces checked

Say for example, If a QI checked total of 450 pieces garments in a day and found total of 45 defects, then the –

DHU = (38 × 100)/450 = 8.44

2. Percent Defective

Percent Defective is the number of total defective pieces found in 100 checked garments items. The formula to calculate Percent Defective is-

Percent Defective = (Total number defective pieces X 100) / Total pieces checked

Say for example, If a QI checked total of 450 pieces garments in a day and found total of 18 defective items, then the –

Percent Defective = (22 × 100)/450 = 4.88%