This document discusses a case study on implementing Acceptance Quality Level (AQL) at a communication manufacturing company to improve productivity and reduce costs. The study found that scratches were the main cause of product rejection. By analyzing current inspection methods and defect data, the company implemented AQL sampling instead of 100% inspection. After AQL implementation, the rejection rate dropped to zero in the second month, meeting the company's quality target and demonstrating that improving quality can increase productivity by reducing costs and wasted time from defects.

1. PRODUCTIVITY IMPROVEMENT: A
CASE STUDY ON ACCEPTANCE
QUALITY LEVEL (AQL)
IMPLEMENTATION AT
COMMUNICATION MANUFACTURING
COMPANY
PRESENTED BY
NAME-SHANKHA SHUBHRA GOSWAMI
M.TECH (PRODUCTION TECHNOLOGY AND
MANAGEMENT)
ROLL-17101203011
PAPER NAME-QUALITY ASSESSMENT AND
CONTROL

2. INTRODUCTION
 In facing the competitive global business environment of
21st century, the manufacturers must respond effectively to the
various demands from the customers. In order to increase
customer loyalty and competitiveness, the manufacturers must
produce products that meet customer requirements and deliver
them at the right time. Hence, the objectives of the
manufacturers should be related to the concept of quality.
 Quality plays an essential factor in order to qualify the
manufacturers to enter the market place since it is
tremendously emphasized in nowadays business. The quality
tools and techniques help manufacturers to have long term
dividends through productivity improvement.

3.  According to Sower (2006), acceptance sampling is an
approach to sampling a lot in order to determine whether the lot
should be rejected or accepted. Compared to 100 percent
inspection, the sampling plan is more practical to be used since
the 100 percent inspection always lead to waste in cost and
time. Acceptance Quality Level (AQL) is use as a standard
guideline for the manufacturer to maintain their performance to
achieve 100 percent zero defect.

4. PROBLEM STATEMENT
In some communication manufacturing company
(such as ABC company) the cost reduction and
improvement of productivity is a major problem. So
the company needs to implement acceptance quality
level(AQL) to reduce total cost and improve
productivity. This case study was done to implement
AQL to the company by incoming inspection of
window R750R silver display.

5. DATA ANALYZING
 In order to identify the main causes of rejection, the
current problem at the ABC Company had been analyzed
first before taking any action to improve it. This case
study only focused on Window R750R Display Silver at
the incoming inspection process. Before the process can
be investigated, the particular incoming inspection
processes of the Window R750R Display Silver are
described in Figure 1.0 in term of flow chart. The Incoming
Part Quality (IPQ) inspection is carried out using 100 %
inspection.

6. The data was collected through three months by using 100%
inspection method. The Figure 2.0 shows histogram chart for the
percentage of reject items for three months. This result shows
that, the third month have the highest percentage of reject item
which is 7.00% out of 100% compared to the first month
(1.41%) and second month (4.13%).
Incoming Part
Quality from
Supplier or Sub-con
Store
OK IPQ
NG
Inspection
Return Parts to
Store Material
Requirement
Send to Supplier

7. 0
20
40
60
80
100
120
Month1 Month2 Month3
OK %
Reject %
Figure 2.0: Percentage of RejectItems forThree Months

8.  The quantity of reject units then were divided according to the eleven
possible causes that stresses by ABC Company Quality Assurances
Department which are scratches, stain mark, adhesive glue, paint mark,
black dot, white dot or stain, poor coating, glass blur, broken, dirty and case
front problem. The Table 1.0 showed the highest cause of rejection issues
through three months were due to scratches.

NO REJECT DUE TO MONTH 1 MONTH 2 MONTH 3 TOTAL
1 Scratches 47 75 89 211
2 Stain Mark 11 57 - 68
3 Adhesive Glue 16 13 17 46
4 Paint Mark - - - -
5 Black Dot 10 6 10 26
6 White Dot/Stain - 12 74 86
7 Poor Coating - 1 - 1
8 Blurry Display 5 - - 5
9 Broken - 1 - 1
10 Dirty 10 - - 10
11 Case Front Problem - - 20 20

9.  In order to determine the exact and most likely causes of major
defect, a brainstorming session was carried out with the Quality
Assurance technical officer of ABC Company. Through this
session, all the possible causes including major and minor causes
were listed in the Cause and Effect Diagram. It can be
summarized that scratches is the main cause of rejection of
Window R750R Display Silver. There are a lot of possibilities that
can cause the scratches. In order to determine and break-down the
causes of scratches, one of QC tools – Cause and Effect Diagram;
is being implemented in this case study as shown in Figure 3.0
The main ‘bone’ structure or branches of the diagram are Man
Power, Environment, Material, Method and Machine.

10. Root causes analysis for scratches ABC Company

11. IMPLEMENTATION OF ACCEPTANCE QUALITY
LEVEL (AQL)
 Compared to 100% inspection which is often not practical, acceptance
sampling is an approach to determine whether the lot should be accepted or
rejected. Sampling inspection is more practical to be used due to time
constraint and the cost of implementation which is extremely high for
100% inspection. Based on the analysis, AQL is recommended to be
implementing in the ABC Company as a way to reduce the defects.

 At the IPQ inspection, instead of using 100% inspection, the inspection
process is now used sampling plan chart to inspect incoming parts
including Window R750R Display Silver. Table 2.0 shows the sample
size code letter which the lot size is used to indicate the inspection level
to be used. The code letter will be used to determine the sample size
which then contribute to the Acceptance Quality Level table (Table 3.0)
that the shows the quantity of acceptable and reject

12. BATCH SIZE INSPECTION LEVEL
2 TO 8 A
9 TO 15 A
16 TO 25 B
26 TO 50 C
51 TO 90 C
91 TO 150 D
151 TO 280 E
281 TO 500 E
501 TO 1200 F
1201 TO 3200 G
3201 TO 10000 G
10001 TO 35000 H
35001 TO 150000 J
150001 TO 500000 J
500001 TO OVER K
Sample size code letter

13. ACCEPTANCE QUALITY LEVEL
STANDARD PART
SAMPLE SAMPLE
CUSTOM,
SAFETY
SIZE SIZE
CRITICAL
CODE OR
LETTER ACCEPT REJECTIS PART
A 2 0 1
B 3 0 1
C 5 0 1
D 8 Reject batch 0 1
E 13 if any of 1 2
F 20 sample is 1 2
defective
G 32 2 3
H 50 3 4
J 80 5 6
K 125 7 8

14.  The Figure shows histogram chart for the percentage of reject items for three
months after the implementation of AQL. In Month 2, ABC Company is
achieved the target with no reject issue on Window R750R Display Silver.
0
20
40
60
80
100
120
MONTH 1 MONTH 2 MONTH 3
OK %
REJECT %

15. DISCUSSION ON RESULTS
 Based from results, the implementation of AQL in ABC
Company showed a huge different result compared to the three
months before implementation. The result showed the drastic
changed in term of quantity of reject parts. Three months after
implementation of AQL were achieved the 100% company target.
Hence, AQL; which a method of quality management; is proven to
be practical to be implement in this company. The productivity of
the company will be in the higher level and lead to achieve the
customer satisfactions. Therefore, it is proven that increasing in
quality will lead to increasing of productivity.

16. RELATION B/W QUALITY-PRODUCTIVITY WITH
TIME AND COST
 Besides, improving the quality also related to the time. It is
proven that the relationship between these two; quality and time
can increase the company’s performance since the sampling
inspection using
 AQL table lead to reduction of time used to inspect parts.

 Quality and productivity also related to the cost. Relationship
of quality and productivity also can bring in more profit to ABC
Company since the reduction in quantity of reject part will lead
to reduction of waste cost and labor cost

17. CONCLUSION
 As the conclusion, the objective which is to obtain through
understanding of quality implementation to the productivity
improvement was met. Based on the understanding through the
literature reviews, the relationship of productivity and quality is
proven in term of graphs and calculation. In order to understand more
about quality, the present quality system in the company was studied
and analyzed. The root cause of the main rejection which is scratches
had been successfully determined. Based on the analysis, the
company is suggested to implement the AQL in incoming inspection
process in order to measure the quality improvement. From the data
gathered, the result shown the drastically changing in term of
quantity of reject of Window R750R Display Silver. The result of
implementing AQL almost achieved the company target which is
100% zero defect. Implement the AQL also lead to drastically change
in cost saved and time saved.

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