Quality Optimization in The Manufacturing Industry: An Application Case.
DECLARATION
I hereby, declared this report entitled “Quality Optimization in the Manufacturing
Industry: An Application Case” is the results of my own research except as cited in
references.
Signature
:
……………………….
Author‘s Name
:
LEE WENG SUM
Date
:
09 April 2010
APPROVAL
This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a
partial fulfillment of the requirements for the degree of Bachelor of Manufacturing
Engineering (Manufacturing Design) with Honours. The member of the supervisory
committee is as follow:
………………………………
(Ms. Muzalna bt. Mohd Jusoh)
(Main Supervisor)
ABSTRACT
This report presents a research on quality optimization in the manufacturing industry.
Nowadays, quality plays an important role in controlling the properties of a product. By
providing optimal quality, the cost for rework or defect could be reduced. This research
mainly focuses on the defects problem in one of the company in the manufacturing
industry, namely ACME Ferrite Products Sdn. Bhd. The objectives of this research were
to identify, analyze and recommend a solution for the defects problem in the
manufacturing industry. The Six Sigma methodology was used in conducting this
research. It is a step-by-step methodology that is consists of 5 important stages, such as
define, measure, analyze, improve and control. As for the data analysis, some of the
quality control tools such as cause and effect diagram, pareto chart, flow chart,
histogram, and control chart were used. The main type of defect, which is dimension
defect, was identified and proper tools will be used to analyze the quality problem. Next,
the major defect was highlighted and analyzed. The root causes of the defects were
investigated in this research and recommendations for improvement were proposed, such
as job rotation, investigation of the significant response in sintering and barreling
process by using Taguchi Method and etc. After improvement is done, some control
steps, such as x bar chart were suggested in order to maintain the outcome of this
research.
i
ABSTRAK
Laporan ini mempersembahkan satu penyelidikan yang melibatkan peningkatan qualiti
dalam industri pembuatan. Pada masa kini, qualiti memainkan satu peranan yang penting
dalam kawalan properti untuk sesebuah produk. Dengan adanya qualiti yang optima, kos
untuk “rework” atau “defect” boleh dikurangkan. Penyelidikan ini mengfokus kepada
masalah “defect” dalam sesebuah kilang industri pembuatan. Objektif penyelidikan ini
adalah untuk mengenalpasti, menganalisa dan mencadangkan penyelesaian untuk
masalah “defect” dalam industri pembuatan. Methodologi “Six-Sigma” digunakan untuk
menjalankan penyelikan ini. Ini merupakan satu methodologi yang mempunyai 5
peringkat yang penting, seperti nyata, ukur, analisa, tingkat dan kawal. Dalam proses
analisa, beberapa alat kawalan qualiti seperti gambah rajah sebab dan implikasi, carta
pareto, carta aliran, histogram dan carta kawalan akan digunakan. Jenis utama “defect”
dikenalpastikan dan alat yang sesuai digunakan untuk menganalisakan masalah qualiti.
Seterusnya, “defect” utama diperhatikan dan kemudian dianalisakan. Faktor-faktor
utama masalah “defect” disiasat dan cadangan untuk peningkatan quality, seperti putaran
tugasan, penggunaan kaedah Taguchi dalam siasatan tanggapan penting dalam process
sintering dan barelling telah diberikan dalam penyelidikan ini. Selepas peningkatan
qualiti dibuat, beberapa langkah kawalan sepert chart x bar juga dicadangkan supaya
pencapaian penyelidikan ini dapat dikekalkan.
ii
DEDICATION
This research is dedicated to my family members and my friends, who express their love,
care, encourage and support to me.
iii
ACKNOWLEDGEMENT
First of all, I would like to thank my supervisor Ms. Muzalna bt. Mohd Jusoh for her
grateful guidance during the course of the final year‘s project. Her valuable advice and
guidance help me a lot and play a very important role in completing this report
successfully.
Next, I would also like to express my appreciation to my fellow friends for their support
and help in this report; especially my roommates Lee Chee Yoong from Robotic and
Automation Course, Soo Sze Wei, and Kwong Soon Yuen from Manufacturing
Management course.
Meanwhile, a special thanks to my lovely family for their understanding and caring
delivered throughout the duration of this project.
Also, I would like to extend my gratitude to Mr Teng Khoon Wai (Senior Process
Engineering Assistant in ACME) for giving me the valuable guidance while doing my
research.
Last but not least, I also want to express my gratitude to UTeM for giving a chance to
me to take part in this final year project and providing some awesome facilities and
services, such as library and online journal database.
iv
TABLE OF CONTENT
Abstract…………………………………………………………………………… i
Abstrak……………………………………………………………………………. ii
Dedication………………………………………………………………………… iii
Acknowledgement…………………………………………………………………. iv
Table of Content…………………………………………………………………… v
List of Tables………………………………………………………………………. ix
List of Figures……………………………………………………………………… xi
List Abbreviations………………………………………………………………….. xiii
1.
INTRODUCTION………………………………………………………… 1
1.1
Project Background……………………………………….……………….. 1
1.2
Problem Statement ……………………………………………................... 3
1.3
Objective……………………………………………………….................... 4
1.4
Scope of Study………………………………………………………..……. 4
2.
LITERATURE REVIEW……………………………………………….. 5
2.1
Definition of Quality……………………………………………………….. 5
2.2
Defects………………………………………………................................... 5
2.3
2.2.1
Defect Life Cycle…………………………………………………... 6
2.2.2
Critical Factors of Defects…………………………………………. 7
Quality Management Philosophy…………………………………………... 8
2.3.1
Deming Philosophy…………………………………………………8
2.3.1.1 Deming‘s 14 Points………………………………………… 9
2.3.1.2 Deming Cycle……………………………………………… 9
2.4
2.3.2
Juran Trilogy……………………………………………………….. 10
2.3.3
Crosby Philosophy…………………………………………………. 11
Tools and Techniques of Quality Improvement…………………………... 11
2.4.1
Total Quality Management (TQM)…………………………………11
v
2.4.2
Kaizen……………………………………………………………… 12
2.4.3
ISO 9000/ QS 9000………………………………………….……... 13
2.4.4
Six-Sigma Methodology…………………………………………… 14
2.4.1
Define………………………………………………………. 15
2.4.2
Measure…………………………………………………….. 16
2.4.3
Analyze…………………………………………………….. 16
2.4.4
Improve…………………………………………………….. 16
2.4.5
Control…………………………………………………….. 16
2.4.5
The Seven Quality Tools (Old & New)……………………………. 20
2.4.6
Other Tools and Techniques……………………………………….. 20
2.5
Quality Improvement Process……………………………………………… 23
2.6
Summary of Previous Researches………………………………………….. 25
2.7
Conclusion…………………………………………………………………. 28
3.
RESEARCH METHODOLOGY……………………………………….. 29
3.1
Methodology …………...………………………………………………….. 29
3.2
3.1.1
Define…………...…………………………………………………. 31
3.1.2
Measure…………...……………………………………………….. 31
3.1.3
Analyze….......................................................................................... 31
3.1.4
Improve…………………………………………………………….. 31
3.1.5
Control…………...………………………………………………… 32
Others Techniques & Method……………………………………………… 32
3.2.1
Observation………………………………………………………… 32
3.2.2
Interview…………………………………………………………… 32
3.3
Current Study of Company Manufacturing Process……………………….. 33
3.3
Gantt Chart for PSM 1 &2 ………………………………………………… 34
4.
COMPANY BACKGROUND…………………………………………… 35
4.1
Introduction………………………………………………………………… 35
4.2
Types of Product…………………………………………………………… 36
4.3
Types of Defects of Baluns Cores (RID) ………………………………….. 38
vi
4.4
Summary…………………………………………………………………… 39
5.
RESULT AND DISCUSSION…………………………………………… 40
5.1
DMAIC Methodology……………………………………………………... 40
5.1.1
Define Phase……………………………………………………….. 40
5.1.2
Measure Phase………………………………………………………42
5.1.2.1 Types of Defects and Yield Percentage……………………. 42
5.1.2.2 Sigma Level…………………………………………………43
5.1.2.3 Evaluation Run for Dimension Defect…………………….. 44
5.1.3
Analyze Phase ………………………………………………………49
5.1.3.1 Types of Defects…………………………………………… 49
5.1.3.2 Yield Percentage…………………………………………… 50
5.1.3.3 Sigma Level…………………………………………………51
5.1.3.4 Potential Causes that Contribute the Defects Problem……...52
5.1.3.5 Process Capability of the Evaluation Run for Dimension
Defect………………………………………………………. 53
5.1.3.6 Summary of Process Capability……………………………. 60
5.1.4
Improve Phase………………………………………………………61
5.1.4.1 Suggestion for Improvement………………………………..61
5.1.5
Control Phase………………………………………………………. 71
5.1.5.1 Control Chart………………………………………………. 71
6.
CONCLUSION AND SUGGESTION…………………………………... 72
6.1
Conclusion…………………………………………………………………. 72
6.2
Suggestion for Future Study……………………………………………….. 73
REFERENCES ……………………………………………………………………74
vii
APPENDICES
A
Defect Analysis Matrix (DAM)
B
Green Cores
C
Sintered Cores
D
Sigma Conversion Table
viii
LIST OF TABLES
2.1
Six-Sigma Tools and Deliverables Matrix
17
2.2
Rating of Process Improvement Techniques
18
2.3
Six Sigma Industrial Applications
19
2.4
Commonly Used Tools and Techniques
22
2.5
Summary of Previous Researches
25
3.1
Gantt Chart for PSM 1 & 2
34
4.1
Types of Product in ACME
36
4.2
Types of Defects and the Description
38
4.3
Types of Defects
39
5.1
Types of Defects and Yield Percentage for RID from July to December
2009
5.2
42
Weekly sigma level for Baluns Cores (RID) from July to December
2009
43
5.3
Specification of Different Parameter
44
5.4a
Dimension ‗A‘ (First Run)
44
5.4b
Dimension ‗A‘ (Second Run)
45
5.4c
Dimension ‗A‘ (Third Run)
45
5.5a
Dimension ‗B‘ (First Run)
46
5.5b
Dimension ‗B‘ (Second Run)
46
5.5c
Dimension ‗B‘ (Third Run)
47
5.6a
Dimension ‗D‘ (First Run)
47
5.6b
Dimension ‗D‘ (Second Run)
48
5.6c
Dimension ‗D‘ (Third Run)
48
5.7
Summary of the Process Capability
60
5.8
Types of Sagger Surfaces
64
ix
5.9
L 9 (3 4) Orthogonal Array used in Taguchi Method for conducting the
experiment
66
5.10
Template for ANOVA method example data
67
5.11
L 9 (3 4) Orthogonal Array used in Taguchi Method for conducting the
experiment
70
x
LIST OF FIGURES
2.1
Defect Cycle
7
2.2
Framework for Quality Improvement of Defective Production
24
3.1
Flow Chart of the Methodology
30
3.2
The Manufacturing Process of the Product in the Company
33
4.1
Baluns Cores (RID)
37
4.2
The product code for Baluns Cores (RID)
37
4.3
Parameter of the dimension for Baluns Cores
37
5.1
Yearly output rate of all products in year 2009
41
5.2
Types of defects
49
5.3
Yield Percentage from July to December of Year 2009
50
5.4
Sigma Level from July to December of Year 2009
51
5.5
Cause-and-Effect Diagram
52
5.6a
Process Capability for dimension ‗A‘ (First Run)
54
5.6b
Process Capability for dimension ‗A‘ (Second Run)
55
5.6c
Process Capability for dimension ‗A‘ (Third Run)
55
5.7a
Process Capability for dimension ‗B‘ (First Run)
56
5.7b
Process Capability for dimension ‗B‘ (Second Run)
57
5.7c
Process Capability for dimension ‗B‘ (Third Run)
57
5.8a
Process Capability for dimension ‗D‘ (First Run)
58
5.8b
Process Capability for dimension ‗D‘ (Second Run)
59
5.8c
Process Capability for dimension ‗D‘ (Third Run)
59
5.9
Overall Process of Baluns Cores (RID)
61
5.10
Process Flow Chart for the Utilization of eSPC
62
5.11
Change in volume from green to sintered core
63
5.12
Sagger with different surfaces
64
xi
5.13
Step No. of the Sagger
65
5.14
Flowchart of the Taguchi Method
65
5.15
Front View of Press machine
68
5.16
Preventive Maintenance Checklist for Press Machine
69
xii
LIST OF ABBREVIATIONS
AHP
-
Analytic Hierarchy Process
AIAG
-
Automotive Industry Action Group
ANOVA
-
Analysis of Variance
CTQ
-
Critical to Quality
DAM
-
Defect Analysis Matrix
DPMO
-
Defect per Million Opportunities
FMEA
-
Failure Mode and Effect Analysis
HPAC
-
Process Attribute Chart
LDA
-
Linear Discriminant Analysis
ODC
-
Orthogonal Defect Classification
PCA
-
Principal Component Analysis
PDPC
-
Process Decision Program Chart
PPM
-
Parts per Million
QA
-
Quality Assurance
QC
-
Quality Control
SPC
-
Statistical Process Control
TQM
-
Total Quality Management
xiii
CHAPTER 1
INTRODUCTION
This report described a project on optimizing the quality in a manufacturing industry.
This chapter explained about the background of project, problem statement, objectives,
and scope of study.
1.1
Project Background
Generally, quality is defined as the measure of excellence or state of being free from
defects, deficiencies, and significant variations. ISO 8402-1986 standard defines quality
as "the totality of features and characteristics of a product or service that bears its ability
to satisfy stated or implied needs." Schneider (2009) said that quality is one of the most
important properties of a product. By providing the optimal quality, the costs for rework,
scrap, recall or even legal actions could be reduced while satisfying customers demand
for reliability. Nowadays, most of the industrial process and products are evaluated by
more than one quality characteristics, such as effectiveness, productivity, safety and
satisfaction.
Quality is actually a system, which, when implemented, yields increased market share
and reduced scrap and rework. Quality is the umbrella if a plethora of process
improvement techniques and theories that starts with a company‘s vendors and extends
beyond the sales of that company‘s products and services to the customer. It is a system
that is built on these provable process improvement techniques, which serve as
components under the umbrella. (Fryman, 2002)
1
Meanwhile, quality is a critical success factor to achieve competitiveness in today‘s
markets. Quality system is designed to set clear view to organization to follow enabling
understanding and involvement of employees proceeding toward common goals. As the
competition increases and consumer demand of high quality of product or services at
reasonable price. A better understanding of the quality is the needs to every company in
order to maintain their competitiveness. There is a increasing of focus on quality
throughout the world. With increased of the competition, companies have recognize
about the important of the quality system to effectively maintain their business. Effective
quality management decreases production costs because the sooner an error is found and
corrected, the less costly it will be.
According to Melissa (2002), quality improvement is necessary for providing a
systematic approach to continuous quality improvement. Continuous improvement
requires the use of cost of quality as a management tool to help gauge the effectiveness
of the quality improvement process. Next, the use of statistical method is vital in
identifying, understanding and continually improves process capability.
Today‘s global business environment calls for organization to develop, implement and
maintain effective quality management system. In recent years, statistical method have
also been explored by banks, insurance companies, government agencies and health care
organizations interested in improving the quality of their services to customers. More
organizations have adopted the use of quality control tools as a mean for obtaining
higher product quality. Although quality control tools are only an element of total
quality management (TQM), it is nevertheless a major one. Quality control is the use of
statistical-based methods to evaluate and monitor process or its input in order to achieve
or maintain a state of control.
In the meanwhile, quality improvement tools are numeric and graphic devices used to
help individuals and teams work with, understand, and improve processes. These tools
were further expanded to become the following seven (old) basic quality control tools
2
such as cause-and-effect diagram, run chart, scatter diagram, flow chart, pareto chart,
histogram and control chart. In 1976, the Japanese Society for Quality Control
Technique Development proposed the seven new tools for quality improvement, for
example, relations diagram, affinity diagram, systematic diagram, matrix diagram,
matrix data analysis, process decision program chart (PDPC) and arrow diagram. These
are the useful tools in conducting this research towards the goals for quality optimization
in the manufacturing industries. (Bauer, 2002)
To achieve product quality improvement, a system which having at least the following
functions such as to predict product quality from operating conditions; to derive better
operating conditions that can improve the product quality; and to detect faults or
malfunctions for preventing undesirable operation has to be developed. (Kano et al.,
2007).
This paper will give an overview of quality improvement by using Six Sigma
Methodology. It will concern about the problem of defects produced in the
manufacturing industry.
1.2
Problem statement
Currently, the ACME Company receives lots of complaint from the customer that they
found that there were large amount of defects detected, especially the dimension of the
cores, lots of cores were out of range of the specification. As a consequence, large
batches of the cores were return back to the company. This may affect the profit of the
company and could receive negative perspective in the point of view of customer. In this
study, the author will practice the six sigma methodology in the company to optimize the
defects problem encountered.
3
1.3
Objective
The main objectives of this research are:
a) to identify the defects problem in the manufacturing industry.
b) to analyze the factors that contributing to defects problem.
c) to recommend a solution for the defects problem of the company
1.4
Scope of Study
The scope of the study focuses on one particular product, namely Baluns Cores (RID).
This study includes identification of the defects problem of the product, quality analysis
for the product, root cause of the defect problem, process capability of the product and
suggestion for improvement will be made. Minitab 14 software was used to conduct the
analysis.
4
CHAPTER 2
LITERATURE REVIEW
This chapter will focus on the study and research of the published materials such as case
study, thesis, journal and some online database. Some related quality topic such as Six
Sigma methodology, quality improvement process, quality tools and etc.
2.1
Definition of Quality
Juran defined quality as fitness for use, Deming said that quality should be aimed at the
needs of the customer, present and future, and the definition of Crosby is that quality is
conformance to requirements (Kolarik, 1995). From these definitions, it is clearly shown
that there is no single definition of quality exists, and it seems that, for a good definition,
the customer, the manufacturer, the product, the technology as well as the processes
should be considered. Whenever there is a need for improvement in the company,
everybody and everything in that company should be involved.
2.2
Defects
Defect is defined as a deviation from specification or, or in other words, the performance
gap between a desired result and an observed result (ISO 8402, 1986). Besides that, the
defect was also defined as the nonfulfilment of intended usage requirements. From this
definition, it should be noted that it covers the departure or absence of one or more
5
quality characteristics from intended usage requirements. The error is the source of a
defect. However, the errors may or may not lead to defects. Such defects are
nonconformities to stated requirements or to human expectations. Defects may or may
not lead to failure when meeting the required specifications, as a defective item may
pass all quality inspections and tests. This is evidence of the fact that not every error
leads to a defect and not every defect results in a failure. Also, a failure may arise from a
combination of defects.
2.2.1 Defect Life Cycle
A variety of defects could be generated by equipment malfunction, process variation,
and an improper process operation (Koleske, 1995). Therefore, manufacturing system
variables affecting product quality are related to operators‘ skills, capability of machines,
human actions during the production process, and workplace environment (Kolarik,
1995). A standard process for the recording and analysis of defects should be developed.
However, it is crucial to produce a model of the life history of a defect. The purpose is to
provide manufacturers with a standard set of states through which a defect occurs. These
states are intended to help standardize defect reporting. This life history illustrates the
time order of the various states of a defect, moving from when a case is first reported to
when it is resolved. The consideration of defects arising from machine faults, operators‘
errors and any other operational sources are included. If measures based on defect status
are gathered, they may be used to learn from the defects and thus improve the
performance of the production line. Figure 2.0 shows the sample of defect cycle. (Dhafr
et al., 2005)
6
Rejected item
Process
Fault
Operator
Error
Confirmed defect
Machine
Fault
Identified defect
Inadequate
Raw Material
Surrounding
Incorrectly
Identified Defect
Resolved detect
Figure 2.1: Defect Cycle (Dhafr et al., 2005)
2.2.2 Critical Factors of Defects
An industrial case studies that related to the production of defects was carried out and
the inspection of production items is carried out visually, through which defect types and
its sources are identified (Dhafr et al. ,2005). An estimation of the probability for a
defect to occur was used to quantify the effect. This is achieved by the use of real data
from actual operations, which can then be used to count the frequency of an individual
defect or total defects on a timely basis; then the probabilities can be calculated based on
the collected data. Some probabilities were lead to the defects to be occurred such as
operator, machine fault and supplier error. The probability of operator error was
measured based on the training matrix with different levels of skill of the operator. For
the machine fault, the probability was figured out by the collection of historical data.
The probability of this type of defect can be measured by the performance of the
supplier, using the ‗parts per million (PPM)‘ data that is generated monthly. Next, the
quantity of finished products that are returned to the supplier due to faulty material will
increase the probability of the error.
7
I hereby, declared this report entitled “Quality Optimization in the Manufacturing
Industry: An Application Case” is the results of my own research except as cited in
references.
Signature
:
……………………….
Author‘s Name
:
LEE WENG SUM
Date
:
09 April 2010
APPROVAL
This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a
partial fulfillment of the requirements for the degree of Bachelor of Manufacturing
Engineering (Manufacturing Design) with Honours. The member of the supervisory
committee is as follow:
………………………………
(Ms. Muzalna bt. Mohd Jusoh)
(Main Supervisor)
ABSTRACT
This report presents a research on quality optimization in the manufacturing industry.
Nowadays, quality plays an important role in controlling the properties of a product. By
providing optimal quality, the cost for rework or defect could be reduced. This research
mainly focuses on the defects problem in one of the company in the manufacturing
industry, namely ACME Ferrite Products Sdn. Bhd. The objectives of this research were
to identify, analyze and recommend a solution for the defects problem in the
manufacturing industry. The Six Sigma methodology was used in conducting this
research. It is a step-by-step methodology that is consists of 5 important stages, such as
define, measure, analyze, improve and control. As for the data analysis, some of the
quality control tools such as cause and effect diagram, pareto chart, flow chart,
histogram, and control chart were used. The main type of defect, which is dimension
defect, was identified and proper tools will be used to analyze the quality problem. Next,
the major defect was highlighted and analyzed. The root causes of the defects were
investigated in this research and recommendations for improvement were proposed, such
as job rotation, investigation of the significant response in sintering and barreling
process by using Taguchi Method and etc. After improvement is done, some control
steps, such as x bar chart were suggested in order to maintain the outcome of this
research.
i
ABSTRAK
Laporan ini mempersembahkan satu penyelidikan yang melibatkan peningkatan qualiti
dalam industri pembuatan. Pada masa kini, qualiti memainkan satu peranan yang penting
dalam kawalan properti untuk sesebuah produk. Dengan adanya qualiti yang optima, kos
untuk “rework” atau “defect” boleh dikurangkan. Penyelidikan ini mengfokus kepada
masalah “defect” dalam sesebuah kilang industri pembuatan. Objektif penyelidikan ini
adalah untuk mengenalpasti, menganalisa dan mencadangkan penyelesaian untuk
masalah “defect” dalam industri pembuatan. Methodologi “Six-Sigma” digunakan untuk
menjalankan penyelikan ini. Ini merupakan satu methodologi yang mempunyai 5
peringkat yang penting, seperti nyata, ukur, analisa, tingkat dan kawal. Dalam proses
analisa, beberapa alat kawalan qualiti seperti gambah rajah sebab dan implikasi, carta
pareto, carta aliran, histogram dan carta kawalan akan digunakan. Jenis utama “defect”
dikenalpastikan dan alat yang sesuai digunakan untuk menganalisakan masalah qualiti.
Seterusnya, “defect” utama diperhatikan dan kemudian dianalisakan. Faktor-faktor
utama masalah “defect” disiasat dan cadangan untuk peningkatan quality, seperti putaran
tugasan, penggunaan kaedah Taguchi dalam siasatan tanggapan penting dalam process
sintering dan barelling telah diberikan dalam penyelidikan ini. Selepas peningkatan
qualiti dibuat, beberapa langkah kawalan sepert chart x bar juga dicadangkan supaya
pencapaian penyelidikan ini dapat dikekalkan.
ii
DEDICATION
This research is dedicated to my family members and my friends, who express their love,
care, encourage and support to me.
iii
ACKNOWLEDGEMENT
First of all, I would like to thank my supervisor Ms. Muzalna bt. Mohd Jusoh for her
grateful guidance during the course of the final year‘s project. Her valuable advice and
guidance help me a lot and play a very important role in completing this report
successfully.
Next, I would also like to express my appreciation to my fellow friends for their support
and help in this report; especially my roommates Lee Chee Yoong from Robotic and
Automation Course, Soo Sze Wei, and Kwong Soon Yuen from Manufacturing
Management course.
Meanwhile, a special thanks to my lovely family for their understanding and caring
delivered throughout the duration of this project.
Also, I would like to extend my gratitude to Mr Teng Khoon Wai (Senior Process
Engineering Assistant in ACME) for giving me the valuable guidance while doing my
research.
Last but not least, I also want to express my gratitude to UTeM for giving a chance to
me to take part in this final year project and providing some awesome facilities and
services, such as library and online journal database.
iv
TABLE OF CONTENT
Abstract…………………………………………………………………………… i
Abstrak……………………………………………………………………………. ii
Dedication………………………………………………………………………… iii
Acknowledgement…………………………………………………………………. iv
Table of Content…………………………………………………………………… v
List of Tables………………………………………………………………………. ix
List of Figures……………………………………………………………………… xi
List Abbreviations………………………………………………………………….. xiii
1.
INTRODUCTION………………………………………………………… 1
1.1
Project Background……………………………………….……………….. 1
1.2
Problem Statement ……………………………………………................... 3
1.3
Objective……………………………………………………….................... 4
1.4
Scope of Study………………………………………………………..……. 4
2.
LITERATURE REVIEW……………………………………………….. 5
2.1
Definition of Quality……………………………………………………….. 5
2.2
Defects………………………………………………................................... 5
2.3
2.2.1
Defect Life Cycle…………………………………………………... 6
2.2.2
Critical Factors of Defects…………………………………………. 7
Quality Management Philosophy…………………………………………... 8
2.3.1
Deming Philosophy…………………………………………………8
2.3.1.1 Deming‘s 14 Points………………………………………… 9
2.3.1.2 Deming Cycle……………………………………………… 9
2.4
2.3.2
Juran Trilogy……………………………………………………….. 10
2.3.3
Crosby Philosophy…………………………………………………. 11
Tools and Techniques of Quality Improvement…………………………... 11
2.4.1
Total Quality Management (TQM)…………………………………11
v
2.4.2
Kaizen……………………………………………………………… 12
2.4.3
ISO 9000/ QS 9000………………………………………….……... 13
2.4.4
Six-Sigma Methodology…………………………………………… 14
2.4.1
Define………………………………………………………. 15
2.4.2
Measure…………………………………………………….. 16
2.4.3
Analyze…………………………………………………….. 16
2.4.4
Improve…………………………………………………….. 16
2.4.5
Control…………………………………………………….. 16
2.4.5
The Seven Quality Tools (Old & New)……………………………. 20
2.4.6
Other Tools and Techniques……………………………………….. 20
2.5
Quality Improvement Process……………………………………………… 23
2.6
Summary of Previous Researches………………………………………….. 25
2.7
Conclusion…………………………………………………………………. 28
3.
RESEARCH METHODOLOGY……………………………………….. 29
3.1
Methodology …………...………………………………………………….. 29
3.2
3.1.1
Define…………...…………………………………………………. 31
3.1.2
Measure…………...……………………………………………….. 31
3.1.3
Analyze….......................................................................................... 31
3.1.4
Improve…………………………………………………………….. 31
3.1.5
Control…………...………………………………………………… 32
Others Techniques & Method……………………………………………… 32
3.2.1
Observation………………………………………………………… 32
3.2.2
Interview…………………………………………………………… 32
3.3
Current Study of Company Manufacturing Process……………………….. 33
3.3
Gantt Chart for PSM 1 &2 ………………………………………………… 34
4.
COMPANY BACKGROUND…………………………………………… 35
4.1
Introduction………………………………………………………………… 35
4.2
Types of Product…………………………………………………………… 36
4.3
Types of Defects of Baluns Cores (RID) ………………………………….. 38
vi
4.4
Summary…………………………………………………………………… 39
5.
RESULT AND DISCUSSION…………………………………………… 40
5.1
DMAIC Methodology……………………………………………………... 40
5.1.1
Define Phase……………………………………………………….. 40
5.1.2
Measure Phase………………………………………………………42
5.1.2.1 Types of Defects and Yield Percentage……………………. 42
5.1.2.2 Sigma Level…………………………………………………43
5.1.2.3 Evaluation Run for Dimension Defect…………………….. 44
5.1.3
Analyze Phase ………………………………………………………49
5.1.3.1 Types of Defects…………………………………………… 49
5.1.3.2 Yield Percentage…………………………………………… 50
5.1.3.3 Sigma Level…………………………………………………51
5.1.3.4 Potential Causes that Contribute the Defects Problem……...52
5.1.3.5 Process Capability of the Evaluation Run for Dimension
Defect………………………………………………………. 53
5.1.3.6 Summary of Process Capability……………………………. 60
5.1.4
Improve Phase………………………………………………………61
5.1.4.1 Suggestion for Improvement………………………………..61
5.1.5
Control Phase………………………………………………………. 71
5.1.5.1 Control Chart………………………………………………. 71
6.
CONCLUSION AND SUGGESTION…………………………………... 72
6.1
Conclusion…………………………………………………………………. 72
6.2
Suggestion for Future Study……………………………………………….. 73
REFERENCES ……………………………………………………………………74
vii
APPENDICES
A
Defect Analysis Matrix (DAM)
B
Green Cores
C
Sintered Cores
D
Sigma Conversion Table
viii
LIST OF TABLES
2.1
Six-Sigma Tools and Deliverables Matrix
17
2.2
Rating of Process Improvement Techniques
18
2.3
Six Sigma Industrial Applications
19
2.4
Commonly Used Tools and Techniques
22
2.5
Summary of Previous Researches
25
3.1
Gantt Chart for PSM 1 & 2
34
4.1
Types of Product in ACME
36
4.2
Types of Defects and the Description
38
4.3
Types of Defects
39
5.1
Types of Defects and Yield Percentage for RID from July to December
2009
5.2
42
Weekly sigma level for Baluns Cores (RID) from July to December
2009
43
5.3
Specification of Different Parameter
44
5.4a
Dimension ‗A‘ (First Run)
44
5.4b
Dimension ‗A‘ (Second Run)
45
5.4c
Dimension ‗A‘ (Third Run)
45
5.5a
Dimension ‗B‘ (First Run)
46
5.5b
Dimension ‗B‘ (Second Run)
46
5.5c
Dimension ‗B‘ (Third Run)
47
5.6a
Dimension ‗D‘ (First Run)
47
5.6b
Dimension ‗D‘ (Second Run)
48
5.6c
Dimension ‗D‘ (Third Run)
48
5.7
Summary of the Process Capability
60
5.8
Types of Sagger Surfaces
64
ix
5.9
L 9 (3 4) Orthogonal Array used in Taguchi Method for conducting the
experiment
66
5.10
Template for ANOVA method example data
67
5.11
L 9 (3 4) Orthogonal Array used in Taguchi Method for conducting the
experiment
70
x
LIST OF FIGURES
2.1
Defect Cycle
7
2.2
Framework for Quality Improvement of Defective Production
24
3.1
Flow Chart of the Methodology
30
3.2
The Manufacturing Process of the Product in the Company
33
4.1
Baluns Cores (RID)
37
4.2
The product code for Baluns Cores (RID)
37
4.3
Parameter of the dimension for Baluns Cores
37
5.1
Yearly output rate of all products in year 2009
41
5.2
Types of defects
49
5.3
Yield Percentage from July to December of Year 2009
50
5.4
Sigma Level from July to December of Year 2009
51
5.5
Cause-and-Effect Diagram
52
5.6a
Process Capability for dimension ‗A‘ (First Run)
54
5.6b
Process Capability for dimension ‗A‘ (Second Run)
55
5.6c
Process Capability for dimension ‗A‘ (Third Run)
55
5.7a
Process Capability for dimension ‗B‘ (First Run)
56
5.7b
Process Capability for dimension ‗B‘ (Second Run)
57
5.7c
Process Capability for dimension ‗B‘ (Third Run)
57
5.8a
Process Capability for dimension ‗D‘ (First Run)
58
5.8b
Process Capability for dimension ‗D‘ (Second Run)
59
5.8c
Process Capability for dimension ‗D‘ (Third Run)
59
5.9
Overall Process of Baluns Cores (RID)
61
5.10
Process Flow Chart for the Utilization of eSPC
62
5.11
Change in volume from green to sintered core
63
5.12
Sagger with different surfaces
64
xi
5.13
Step No. of the Sagger
65
5.14
Flowchart of the Taguchi Method
65
5.15
Front View of Press machine
68
5.16
Preventive Maintenance Checklist for Press Machine
69
xii
LIST OF ABBREVIATIONS
AHP
-
Analytic Hierarchy Process
AIAG
-
Automotive Industry Action Group
ANOVA
-
Analysis of Variance
CTQ
-
Critical to Quality
DAM
-
Defect Analysis Matrix
DPMO
-
Defect per Million Opportunities
FMEA
-
Failure Mode and Effect Analysis
HPAC
-
Process Attribute Chart
LDA
-
Linear Discriminant Analysis
ODC
-
Orthogonal Defect Classification
PCA
-
Principal Component Analysis
PDPC
-
Process Decision Program Chart
PPM
-
Parts per Million
QA
-
Quality Assurance
QC
-
Quality Control
SPC
-
Statistical Process Control
TQM
-
Total Quality Management
xiii
CHAPTER 1
INTRODUCTION
This report described a project on optimizing the quality in a manufacturing industry.
This chapter explained about the background of project, problem statement, objectives,
and scope of study.
1.1
Project Background
Generally, quality is defined as the measure of excellence or state of being free from
defects, deficiencies, and significant variations. ISO 8402-1986 standard defines quality
as "the totality of features and characteristics of a product or service that bears its ability
to satisfy stated or implied needs." Schneider (2009) said that quality is one of the most
important properties of a product. By providing the optimal quality, the costs for rework,
scrap, recall or even legal actions could be reduced while satisfying customers demand
for reliability. Nowadays, most of the industrial process and products are evaluated by
more than one quality characteristics, such as effectiveness, productivity, safety and
satisfaction.
Quality is actually a system, which, when implemented, yields increased market share
and reduced scrap and rework. Quality is the umbrella if a plethora of process
improvement techniques and theories that starts with a company‘s vendors and extends
beyond the sales of that company‘s products and services to the customer. It is a system
that is built on these provable process improvement techniques, which serve as
components under the umbrella. (Fryman, 2002)
1
Meanwhile, quality is a critical success factor to achieve competitiveness in today‘s
markets. Quality system is designed to set clear view to organization to follow enabling
understanding and involvement of employees proceeding toward common goals. As the
competition increases and consumer demand of high quality of product or services at
reasonable price. A better understanding of the quality is the needs to every company in
order to maintain their competitiveness. There is a increasing of focus on quality
throughout the world. With increased of the competition, companies have recognize
about the important of the quality system to effectively maintain their business. Effective
quality management decreases production costs because the sooner an error is found and
corrected, the less costly it will be.
According to Melissa (2002), quality improvement is necessary for providing a
systematic approach to continuous quality improvement. Continuous improvement
requires the use of cost of quality as a management tool to help gauge the effectiveness
of the quality improvement process. Next, the use of statistical method is vital in
identifying, understanding and continually improves process capability.
Today‘s global business environment calls for organization to develop, implement and
maintain effective quality management system. In recent years, statistical method have
also been explored by banks, insurance companies, government agencies and health care
organizations interested in improving the quality of their services to customers. More
organizations have adopted the use of quality control tools as a mean for obtaining
higher product quality. Although quality control tools are only an element of total
quality management (TQM), it is nevertheless a major one. Quality control is the use of
statistical-based methods to evaluate and monitor process or its input in order to achieve
or maintain a state of control.
In the meanwhile, quality improvement tools are numeric and graphic devices used to
help individuals and teams work with, understand, and improve processes. These tools
were further expanded to become the following seven (old) basic quality control tools
2
such as cause-and-effect diagram, run chart, scatter diagram, flow chart, pareto chart,
histogram and control chart. In 1976, the Japanese Society for Quality Control
Technique Development proposed the seven new tools for quality improvement, for
example, relations diagram, affinity diagram, systematic diagram, matrix diagram,
matrix data analysis, process decision program chart (PDPC) and arrow diagram. These
are the useful tools in conducting this research towards the goals for quality optimization
in the manufacturing industries. (Bauer, 2002)
To achieve product quality improvement, a system which having at least the following
functions such as to predict product quality from operating conditions; to derive better
operating conditions that can improve the product quality; and to detect faults or
malfunctions for preventing undesirable operation has to be developed. (Kano et al.,
2007).
This paper will give an overview of quality improvement by using Six Sigma
Methodology. It will concern about the problem of defects produced in the
manufacturing industry.
1.2
Problem statement
Currently, the ACME Company receives lots of complaint from the customer that they
found that there were large amount of defects detected, especially the dimension of the
cores, lots of cores were out of range of the specification. As a consequence, large
batches of the cores were return back to the company. This may affect the profit of the
company and could receive negative perspective in the point of view of customer. In this
study, the author will practice the six sigma methodology in the company to optimize the
defects problem encountered.
3
1.3
Objective
The main objectives of this research are:
a) to identify the defects problem in the manufacturing industry.
b) to analyze the factors that contributing to defects problem.
c) to recommend a solution for the defects problem of the company
1.4
Scope of Study
The scope of the study focuses on one particular product, namely Baluns Cores (RID).
This study includes identification of the defects problem of the product, quality analysis
for the product, root cause of the defect problem, process capability of the product and
suggestion for improvement will be made. Minitab 14 software was used to conduct the
analysis.
4
CHAPTER 2
LITERATURE REVIEW
This chapter will focus on the study and research of the published materials such as case
study, thesis, journal and some online database. Some related quality topic such as Six
Sigma methodology, quality improvement process, quality tools and etc.
2.1
Definition of Quality
Juran defined quality as fitness for use, Deming said that quality should be aimed at the
needs of the customer, present and future, and the definition of Crosby is that quality is
conformance to requirements (Kolarik, 1995). From these definitions, it is clearly shown
that there is no single definition of quality exists, and it seems that, for a good definition,
the customer, the manufacturer, the product, the technology as well as the processes
should be considered. Whenever there is a need for improvement in the company,
everybody and everything in that company should be involved.
2.2
Defects
Defect is defined as a deviation from specification or, or in other words, the performance
gap between a desired result and an observed result (ISO 8402, 1986). Besides that, the
defect was also defined as the nonfulfilment of intended usage requirements. From this
definition, it should be noted that it covers the departure or absence of one or more
5
quality characteristics from intended usage requirements. The error is the source of a
defect. However, the errors may or may not lead to defects. Such defects are
nonconformities to stated requirements or to human expectations. Defects may or may
not lead to failure when meeting the required specifications, as a defective item may
pass all quality inspections and tests. This is evidence of the fact that not every error
leads to a defect and not every defect results in a failure. Also, a failure may arise from a
combination of defects.
2.2.1 Defect Life Cycle
A variety of defects could be generated by equipment malfunction, process variation,
and an improper process operation (Koleske, 1995). Therefore, manufacturing system
variables affecting product quality are related to operators‘ skills, capability of machines,
human actions during the production process, and workplace environment (Kolarik,
1995). A standard process for the recording and analysis of defects should be developed.
However, it is crucial to produce a model of the life history of a defect. The purpose is to
provide manufacturers with a standard set of states through which a defect occurs. These
states are intended to help standardize defect reporting. This life history illustrates the
time order of the various states of a defect, moving from when a case is first reported to
when it is resolved. The consideration of defects arising from machine faults, operators‘
errors and any other operational sources are included. If measures based on defect status
are gathered, they may be used to learn from the defects and thus improve the
performance of the production line. Figure 2.0 shows the sample of defect cycle. (Dhafr
et al., 2005)
6
Rejected item
Process
Fault
Operator
Error
Confirmed defect
Machine
Fault
Identified defect
Inadequate
Raw Material
Surrounding
Incorrectly
Identified Defect
Resolved detect
Figure 2.1: Defect Cycle (Dhafr et al., 2005)
2.2.2 Critical Factors of Defects
An industrial case studies that related to the production of defects was carried out and
the inspection of production items is carried out visually, through which defect types and
its sources are identified (Dhafr et al. ,2005). An estimation of the probability for a
defect to occur was used to quantify the effect. This is achieved by the use of real data
from actual operations, which can then be used to count the frequency of an individual
defect or total defects on a timely basis; then the probabilities can be calculated based on
the collected data. Some probabilities were lead to the defects to be occurred such as
operator, machine fault and supplier error. The probability of operator error was
measured based on the training matrix with different levels of skill of the operator. For
the machine fault, the probability was figured out by the collection of historical data.
The probability of this type of defect can be measured by the performance of the
supplier, using the ‗parts per million (PPM)‘ data that is generated monthly. Next, the
quantity of finished products that are returned to the supplier due to faulty material will
increase the probability of the error.
7