Acceptable Quality Level
‘Acceptable Quality Level’ and is defined as the percentage of defective pieces which are
tolerated/accepted by the buyer from the manufacturer. In other words, it's the quality level
that is least tolerable.
To ensure the right quality products, an AQL chart has to follow during inspection of apparel
which varies from product to product, process to process and even buyer to buyer. Acceptable
Quality Level (AQL) has great importance in ready-made apparel business.
It is expressed in a percentage (%) number of average defective items where
average defective item is the multiple result of total number of defective items found during
inspection and total number of items inspected.
The Acceptable Quality Level differs from process to process, product to product and buyer to
buyer.
Acceptance Quality Level (AQL) refers to the maximum number of defective items that could
be considered accepted during the random sampling of and inspection. The defects that are
found during inspection are classified into 3 categories:
Critical: Must be 100% accurate. There is no range.
Major: Normally 2.5%
Minor : Normally 4%
For consumer goods, faults or defects which are found during random sampling or inspections
are classified into four categories:
Critical defects: Garment must be 100% accurate. (there is no range, and critical defects
are entirely unacceptable.)
Major defects: Normally 2.5% (products would be considered unacceptable by end
users)
Minor defects: Normally 4% (product slightly doesn’t meet specifications, but end user
won’t mind it.)
Slight defects: Normally 6.5% (defect is only recognizable internally)
Furthermore, the garment industry identifies 6 types of acceptable quality level standards, as
indicated below:
Acceptable Quality Level 1%
Acceptable Quality Level 1.5%
Acceptable Quality Level 2.5%
Acceptable Quality Level 4%
Acceptable Quality Level 6.5%
Acceptable Quality Level 10%
1 Engr. F. Islam Surjo, Lecturer, TE, CU
The acceptable quality level standard used during inspections is subject to the price and quality
of the product. Generally, a lower figure acceptable quality level standard (1%) is used for
higher priced, higher quality garments whereas a higher figure standard (10%) is used for
lower priced, lower quality garment.
A standard acceptance quality level for a garment factory is 2.5% for major defects and 4.0 for
minor defects. Additionally, critical defects normally require a zero tolerance acceptance level
and any products that fail to meet the set acceptance quality level will undergo 100%
inspection.
Sampling Method:
o Single Sampling method
o Double Sampling method
o Multiple Sampling method
But this is not possible, as the acceptance decision is made only on the basis of small sample
drawn from the lot and it carries a risk of making a wrong judgment.
Single sampling plan - Normal inspection:
Assurance an AQL of 2.5 % and a lot size of 1200 garments and the sample size
is 80 garments. If the number of defective garments found is 5 the total lot is "Acceptable"
suppose if the defective garments found is 6, the total lot is "Reject/ Re-Check".
Double sampling plan - Normal Inspection:
Assurance an AQL 4.0% and a lot size is 1200 garments and the sample size is
80 garments. If the Number of defective garments found is 7, the total lot is "Acceptable"
suppose if the defective garments found is 8 the total lot is "Reject/ Re-Check".
For Example:
Total garments (lot Size) 1200 garments
Sample size (selected for inspection) 80 garments
AQL 2.5 / 4.0
If the major defective found is 5 and minor defective found
is 7 the total garments is "Acceptable".
If the defective exceed (Above 5 major and 7 Minor), the
total garments is Reject / Re-check.
2 Engr. F. Islam Surjo, Lecturer, TE, CU
AQL Chart for Apparel Industry
This chart is a tool provided to help determine the sample lot. The effectiveness and efficiency
of a quality audit largely depend upon proper audit execution.
This means:
1. Correct selection of sampling lot.
2. Good random sample pick-up.
3. Accurate classification of defects.
AQL chart need in Garments industry to do quality inspection, lot by lot AQL Audit. AQL chart
systems are like 1.0, 1.5, 2.5, 4.0.
AQL chart for Garments inspection:
AQL-4.0:
As per above AQL chart, if lot size 4000 then audit quantity will be 80 pcs. Major defects
quantity among audit quantity 5 or less than 5 will be passed or more than 5 defects will be
failed or rejected in Audit.
AQL-2.5:
Suppose we follow AQL 2.5. As per above AQL chart, if lot size 4000 then audit quantity
will be 80 pcs. Major defects quantity among audit quantity 5 or less than 5 will be
passed or more than 5 defects will be failed or rejected in Audit.
Suppose we follow AQL 2.5. As per above AQL chart, if lot size 12500 then audit
quantity will be 125 pcs. Major defects quantity among audit quantity 7 or less than 7
will be passed or more than 7 defects will be failed or rejected in Audit.
AQL-1.5:
Suppose we follow AQL 1.5. As per above AQL chart, if lot size 4000 then audit quantity
will be 80 pcs. Major defects quantity among audit quantity 2 or less than 2 will be passed or
more than 2 defects will be failed or rejected in Audit.
3 Engr. F. Islam Surjo, Lecturer, TE, CU
Read AQL Table
It is very easy process. Now terms of AQL table are given below:
Lot or Batch size: This means total how many pieces inspector is going to
check or inspect.
Sample size Code letter: This code is indicative a range of batch size.
Sample size: It means that how many pieces will be picked up for inspection
from the total offered pieces (Batch).
Ac (Accepted): The number in this column denotes that if the inspector finds
up to that many defective pieces the shipment will be accepted by buyer.
Re (Rejected): On the other hand number in this column denotes that if the
inspector finds that much defective pieces or more than the listed number, the
shipment will be rejected (or asked to the manufacturer for 100% inspection and
re-offer for final inspection) by buyer.
In the garment industry, the following Acceptable Quality Level chart is
used:
4 Engr. F. Islam Surjo, Lecturer, TE, CU
The AQL is expressed in a percentage number of average defective items and can
be calculated using the following formula:
Average defective item =
No. of defective item found during inspection / Total no. of item inspection x 100
AQL Audit system in Garments industry
First of all check lot quantity. As per AQL Audit requirement, auditor pick audit/ sample
quantity randomly from every lot, like a lottery. Then auditor checks garments from picked
sample quantity and count defect. If defect quantity exceed acceptable limit, audit result is
“failed” or “rejected” that inspected lot
AQL Audit
AQL is Acceptable Quality Limit or Acceptable Quality Level (AQL), a sampling of quality audit
or inspection system, use for quality audit or inspection process in Garments industry. AQL
sampling information shows in an AQL chart, QC use for in Quality Audit when 100% quality
inspection is not possible. AQL inspection use in Fabrics roll sampling, trims inspection,
cutting panel inspection, Sewing, Finishing and Final Inspection. Though there is 100%
inspection also available in sewing and finishing but AQL audit is done for checking quality
control process. There is various type of AQL sampling plan in the world, I given most
commonly using 3 types AQL chart.
Why we need AQL Audit
When you want to check quality inspected goods or you do not have time to check 100% goods
you can do AQL audit. Final inspection is done in AQL Audit; factories have internal AQL audit
system. To check supplier’s fabrics and Trims quality, you need AQL audit in suppliers Raw
materials. Sewing end line and operator bundle wise AQL audit also done in apparel industry.
Uses of AQL Audit in Garments Industry:
Fabrics Roll sampling for inspection
Trims and Accessories inspection
Cutting panel inspection
Sewing Quality Audit
Finishing Quality Audit
Finishing inline inspection
Pre-final Inspection
Final inspection
5 Engr. F. Islam Surjo, Lecturer, TE, CU
