What is DHU? How to Measure It?

Question: I want to know more about DHU in quality control. Can you please elaborate on this term?

Answer:

There are two common quality measures used in garment manufacturing

Number of defects and
Number of defective garments found in inspected garments (checked garments)

To understand DHU, first, you have to know the term ‘defects’ in garments and ‘defective garment’. To many people, these two terms are not completely clear. The terms defect and defective have been explained here.

In the garment production processes, quality checking stations are installed to stop defect generation at the source. And stopping defective garments from moving to the following production processes. Normally, garment checking is done for raw materials, partially stitched garments, stitched garments, and finished garments by quality checkers.

In checking, the quality checker detects defects in garments and separates defective garments from good pieces. Where there is an established quality system, the quality checker records the total number of defects found in the garments checked by her/him in a day. Checkers records the number of defective garments where those defects are found.

Quality checking records are summarized and the result is presented in DHU.

What is DHU?

DHU stands for Defect per Hundred Units. It means the number of defects found or detected per 100 garments. This is also known as DPHU (Defects Per Hundred Units).

DHU value is calculated using the following formula.

Defects per hundred units = (Total defects found/Total garments inspected) *100

An example:

Assume that a finishing checker checked 250 garments in a day. Checker found 20 defective garments and he found 35 defects in those defective pieces. What is the DHU of the finishing process?

Solution: By using the above formula DHU of the finishing goods is

= (35/250)* 100
= 14

How to measure DHU?

To measure the DHU of any process, one needs to record the number of total pieces checked and the number of total defects detected in the inspected garments.

It is a number of defects, not the defective garments. One defective garment may have more than one defect. Let’s say, a checker has checked only one item (shirt) and found a broken stitch, a hole, and raw edges in it. Here checker found one defective shirt but the defective shirt contains 3 defects.

Once you have a record of the following information of a lot you can measure the DHU of that lot using the above formula.

Total pieces inspected
Total defects found in those inspected pieces

Data collection format for DHU report

The following template can be used for data capturing during the garment inspection. When a checker checks garments or other items, he needs to write tally marks on the inspection form to count defects found in the checked garment. Later, at the end of the day, summarised the collected data and calculate DHU.

I hope you have understood it completely now? Please post your comments and share this post if you find this helpful.