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UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Autonomous Maintenance Programme on
Grinding Machine for Job Base
Report submitted in accordance with the requirements of the Universiti Teknikal
Malaysia Melaka for the Bachelor’s Degree in Manufacturing Engineering
(Manufacturing Management)
By
Ilyana Binti Abdullah
Faculty of Manufacturing Engineering
April 2008
oval
UTeM Library (Pind.1/2005)
UNIVERSITI TEKNIKAL MALAYSIA MELAKA (UTeM)
BORANG PENGESAHAN STATUS TESIS*
JUDUL: AUTONOMOUS MAINTENANCE PROGRAMME ON GRINDING MACHINE FOR JOB BASE.
SESI PENGAJIAN: 2007/2008
Saya ILYANA BINTI ABDULLAH
mengaku membenarkan tesis (PSM/Sarjana/Doktor Falsafah) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:
1. Tesis adalah hak milik Universiti Teknikal Malaysia Melaka. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan
untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran
antara institusi pengajian tinggi.
4. **Sila tandakan (√)
SULIT
TERHAD
TIDAK TERHAD
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia yang termaktub di dalam
AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang telah ditentukan
oleh organisasi/badan di mana penyelidikan dijalankan)
(TANDATANGAN PENULIS)
Alamat Tetap: NO. 97 FELDA KEMAHANG 2, 17510 TANAH MERAH, KELANTAN Tarikh: 29 APRIL 2008
Disahkan oleh:
(TANDATANGAN PENYELIA)
Cop Rasmi: Tarikh: ________________
* Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah dan Sarjana secara penyelidikan, atau disertasi bagi pengajian secara kerja kursus dan penyelidikan, atau Laporan Projek Sarjana Muda (PSM). ** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT atau TERHAD.
iii
DECLARATION
I hereby, declared this Bachelor’s Project entitled “Autonomous Maintenance
Programme on Grinding Machine for Job Base” is the result of my own research except
as cited in references.
Signature :
Author’s Name : Ilyana Binti Abdullah
Date :
iv
APPROVAL
This Bachelor’s Project submitted to the senate of UTeM and has been accepted as
fulfilment of the requirement for the Degree of Bachelor of Manufacturing Engineering
(Manufacturing Management) with Honours. The member of the supervisory committee
is as follow:
…………………………………………
Mr. Wan Hasrulnizzam Wan Mahmood
Project Supervisor
Faculty of Manufacturing Engineering
v
ABSTRACT
The heart of Total Productive Maintenance (TPM) is Autonomous Maintenance (AM),
whose mainly principle lies in the first three steps of AM; Initial Cleaning,
countermeasure at the source of the problems and cleaning and lubricating standard. This
project spanned over a time period of seven weeks (16 January 2008 – 5 March 2008) on
the shop floor of UTeM’s Machine Shop Lab for performing the first three steps of AM
on grinding machine (Model: BO 300A). There are three types of abnormalities (fuguai)
identified; safety, physical, and function. The result shows that physical fuguai is a
chronic problem whereas safety and function are more acute problem to the machine. A
number of fuguai are difficult to be eliminated and some of them required high technical
knowledge to be removed.
vi
ABSTRAK
Penyelenggaraan Sendiri (AM) ialah jantung kepada TPM yang mana prinsipnya adalah
berkaitan dengan 3 langkah utama dalam AM; Pembesihan Awal, cara mengatasi
masalah pada peringkat punca masalah bermula, dan keseragaman pembersihan dan
lubrikasi Projek ini dilaksanakan selama 7 minggu (16 Januari 2008 – 5 Mac 2008) di
bahagian bengkel mesinsyop, UTeM dengan tujuan dan matlamat untuk melaksanakan 3
langkah awal di dalam AM pada mesin pencanai (Model: BO 300A). Terdapat tiga jenis
kecacatan (fuguai) yang dijumpai iaitu kecacatan keselamatan, fizikal,dan fungsi. Hasil
daripada projek ini menunjukkan bahawa kecacatan fizikal adalah masalah kronik kepada
mesin sementara kecacatan fungsi dan kecacatan keselamatan adalah masalah genting
kepda mesin. Beberapa kecacatan dikenal pasti adalah sukar untuk dihapuskan dan
sebahagiannya memerlukan kepakaran teknikal yang tinggi untuk dihapuskan.
vii
DEDICATIONS
For my beloved parents:
Abdullah Bin Omar
Che Mah Binti Che Noh
For my cherish brothers and sisters
And my treasured friends
viii
ACKNOWLEDGEMENTS
Bismillahirrahmanirrahim…
This thesis would not have been possible without the contribution of several important
people.There is a number of people I want to thank for their help and support in writing
this thesis. Some of them are legends, like Taichi Ohno, Shigeo Shingo, W. Edwards
Deming, and Siiechi Nakajima. Others have become anonymous in the mist of time.
A special word of thanks is due to the people closer to me. Friends and colleagues who
gave me opportunity to develop my writing, all UTeM lecturers and staffs especially to
my PSM Supervisor, Mr. Wan Hasrulnizzam Bin Wan Mahmood who have taught and
relayed the techniques and knowledge. I believe his guidance and advice has made this a
much better thesis.
Last, but not least, my gratitude to my family who have shown an extraordinary amount
of patience and tolerate in supporting me writing this thesis. And with the blessing of
Allah I could finish this thesis. My thanks and gratitude to you all.
Ilyana Binti Abdullah
ix
TABLE OF CONTENTS
Declaration …………………………………………………………...……………..…iii
Approval..................................................................................................................…...iv
Abstract………………………………………………………………………………...v
Abstrak………………………………………………………………………………...vi
Dedication………………………………………………………………..…………....vii
Acknowledgements..............................................................................................…....viii
Table of Contents…………………………………………………………........……...ix
List of Figures .......................................................................................................…..xiii
List of Tables ………………………………………………………………...............xvi
List of Abbreviations, Symbols, Specialized Nomenclature…………………...…...xviii
1. INTRODUCTION………………………………………………………………….1
1.1 Background……………………………………………………………………….1
1.2 Objectives……………………………………………………………………….. 2
1.3 Scope……………………………………………………………………………..2
1.4 Importance of Project…………………………………………………………….3
1.5 Outline of report ………………………………………………………………….3
2. MAINTENANCE ………………………………………………………………….5
2.1 Introduction to Maintenance…………………………………………………....5
2.2 Evolution of Maintenance Concept………………………………………….....7
2.3 Importance of Maintenance…………………………………………...…….….9
2.4 Types of Maintenance ………………………………………………………...10
2.4.1 Breakdown Maintenance………………………………………………….11
2.4.2 Preventive Maintenance (PM)……………………………………………12
2.4.3 Predictive Maintenance…………………………………………………...13
2.4.4 Time Based Maintenance (TBM) Also Called Periodic maintenance……13
2.4.5 Corrective Maintenance…………………………………………………..14
2.4.6 Failure - Finding Maintenance……………………………………………15
2.4.7 Reactive Maintenance…………………………………………………….15
x
2.4.8 Reliability-Centered Maintenance (RCM)………………………………. 15
2.5 Total Productive Maintenance (TPM)…………………………… …………..16
2.5.1 TPM Definitions…………………………………………….…………….16
2.5.2 Pillars of TPM……………………………………………….…………… 20
2.5.2.1 Pillar 1- 5S……………..………………………...…….……………...21
2.5.2.2 Pillar 2 - AM or Jishu Hozen (JH)……………………………………22
2.5.2.3 Pillar 3 - Kobetsu Kaizen……………………………………………...23
2.5.2.4 Pillar 4 - Planned Maintenance…………………….………………….24
2.5.2.5 Pillar 5 - Quality Maintenance…………………………….…………..25
2.5.2.6 Pillar 6 - Training and Education……………………….……………..25
2.5.2.7 Pillar 7 - Office TPM…………………………… ……………………27
2.5.2.8 Pillar 8 - Safety, Health and Environment…………………………….27
2.5.3 Overall Equipment Effectiveness (OEE)………………………………….28
2.6 Autonomous Maintenance…………………………………………………….31
2.6.1 Introduction to Autonomous Maintenance………………………………..31
2.6.2 Steps to Autonomous Maintenance……………………………………….32
2.6.2.1 Step Zero……………………………………………………...………32
2.6.2.2 Step 1- Initial Cleanup…………………………………………….…..33
2.6.3.3 Step 2- Counter Measures…………………………………………….34
2.6.3.4 Step 3- Cleaning and Lubrication Standard…………………………...36
2.6.3.5 Step 4- General Inspection……………………………………………36
2.6.3.6 Step 5- Autonomous Inspection………………………………………37
2.6.3.7 Step 6- Organization and Tidiness……………………………………38
2.6.3.8 Step 7- Full Autonomous Maintenance……………………………….39
2.6.3 Fuguai …………………………………………………………………….39
3. GRINDING MACHINE (MODEL: BO 300 A) ………………………………...41
3.1 Grinding Machine……………………………………………………………..41
3.1.1 Types of Grinding Machine……………………………………………….41
3.1.2 Grinding Wheels…………………………………………………………..43
3.1.3 Grinding Fluids……………………………………………………………45
3.2 Grinding Machine (Model: BO 300 A)……………………………………….46
3.2.1 Technical Data………………………………………………………………47
3.2.2 Operating Instruction……………………………………………………..50
xi
3.2.3 Safety Rules……………………………………………………………….51
3.3 Troubleshooting……………………………………………………………….52
4. METHODOLOGY……………………………………………………………….54
4.1 Planning of the Project………………………………………………………..54
4.1.1 Process Flow………………………………………………………………54
4.1.2 Gantt Chart………………………………………………………………...57
4.2 Data Collection………………………………………………………………..58
4.2.1 Primary Data………………………………………………………………...59
4.2.1.1 Field Observation……………………………………………………...59
4.2.1.2 Archival Collections…………………………………………………...59
4.2.1.3 Fuguai Investigation…………………………………………………...59
4.2.1.4 Focus Group Discussion…………………………………………….....60
4.2.1.5 Site Visit………………………………………………………………..60
4.2.2 Secondary Data………………………………………………………….…60
4.2.3 Analytical Technique………………………………………………………61
4.2.3.1 Frequency vs Fuguai…………………………………………………...61
4.2.3.2 Fuguai vs Area…………………………………………………………62
4.2.3.3 Fuguai Analysis ……………………………………………………….62
5. ANALYSIS AND DISCUSSION S………………………………………………...64
5.1 Initial Cleaning………………………………………………………………….64
5.1.1 Fuguai Characteristic……………………………………………………….65
5.1.2 Defect Map on Grinding Machine (Model: BO 300A) ……………………69
5.2 Analysis of Fuguai……………………………………………………………..71
5.2.1 Analysis of Fuguai versus Frequency………………………………………..72
5.2.2 Analysis of Fuguai versus Area……………………………………………77
5.2.3 Analysis of Types of Fuguai……………………………………………… 81
5.3.3 Why-Why Analysis………………………………………………………...85
6. CONCLUSIONS AND RECOMMENDATIONS……………………….………..94
6.1 Conclusions……………………………………………………………….…….94
xii
6.2 Recommendations………………………………………...……..…………….95
6.2.1 Current Study……………………………………………………………...95
6.2.2 Future Studies……………………………………………………………..97
7. REFERENCES…………………………………………………………………….98
APPENDICES
A Main Spreadsheet for Fuguai Analysis
B Check Sheet for Frequency of Each Fuguai Description
C Check Sheet for Area of Each Fuguai Description
D Check Sheet for Area of Each Fuguai Types
xiii
LIST OF FIGURES
NO TITLE PAGE
2.1 The Evolution of Maintenance Concept 8
2.2 The Importance of Maintenance 10
2.3 Types of Maintenance 11
2.4 Six Major Losses in Productivity 20
2.5 5S Pillars in TPM 20
2.6 Seven Steps for Developing Autonomous Maintenance 22
2.7 Improvement Categories 23
2.8 Six Steps in Planned Maintenance 24
2.9 Phase of Skills 26
2.10 Overall Equipment Effectiveness Model 30
2.11 Design of Autonomous Maintenance 33
2.12 Example of “Why-Why” Analysis 35
2.13 Step 4-General Inspection 37
2.14 Step 5-Autonomous Inspection 38
3.1 An Example of Belt Grinder 42
3.2 An Example of Bench Grinder 42
3.3 An Example of Cylindrical Grinder 42
3.4 An Example of Surface Grinder 43
3.5 An Example of Tool and Cutter Grinder 43
3.6 An Example of Tool and Cutter Grinder 43
3.7 Straight Wheel 44
3.8 Cylinder Wheel 44
xiv
NO TITLE PAGE
3.9 Tapered Wheel 41
3.10 Straight Cup Wheel 41
3.11 Flaring Cup Wheel 41
3.12 Dish Wheel 42
3.13 Saucer Wheel 42
3.14 Grinding Machine (Model: BO 300 A) 47
3.15 Orthographic- Technical Drawing for Grinding Machine 48
(Model: BO 300A)
3.16 Isometrics- Technical Drawing for Grinding Machine 49
(Model: BO 300A)
3.17 Operating Instruction of Grinding Machine (Model: BO 300A) 50
4.1 The Process Flow of the Project 56
4.2 Red Tag 63
4.3 Blue Tag 63
5.1 Dust 65
5.2 Coolant Spill 65
5.3 Corrosion 65
5.4 Cobweb 66
5.5 Scratches 66
5.6 Broken Hose 66
5.7 Misspelling Label 66
5.8 Misplace item 66
xv
NO TITLE PAGE
5.9 Area1:- Front 67
5.11 Area3:- Left Side 68
5.12 Area1 Tagged with F-Tags 69
5.13 Area2 and Area3 are Tagged with F-Tags 70
5.14 The Trend Chart of Fuguai vs Week 73
5.15 The Pareto Chart for Fuguai. 74
5.16 Fuguai and Weekly Chart 76
5.17 Percentage of Fuguai for Each Area 79
5.18 Fuguai Frequency versus Area 80
5.19 Trend of Fuguai for Each Area 81
5.20 Trend of Types of Fuguai Frequency versus Week 83
5.21 Types of Fuguai versus Week for Area 1: Front 84
5.22 Types of Fuguai versus Week for Area 2: Right Side 84
5.23 Types of Fuguai versus Week for Area 3: Left Side 85
5.24 Area 1: Front before Initial Cleaning 86
5.25 Area 1: Front after Initial Cleaning 86
5.26 Area 2: Right Side before Initial Cleaning 86
5.27 Area 3: Left Side before Initial Cleaning 86
5.28 Area 2: Right Side after Initial Cleaning 86
5.29 Area 2: Right Side before Initial Cleaning 86
xvi
LIST OF TABLES
NO TITLE PAGE
2.1 Definition of TPM letters-acronym 17
2.2 The Definitions of 5S 21
3.1 Types of Grinding Machine 42
3.2 Standard Types of Grinding Wheels 44
3.3 Technical Data of Grinding Machine 46
3.4 Grinding machine Troubleshooting 52
4.1 Gantt Chart of the Project 57
4.2 The Differences between Primary and Secondary Data 58
4.3 The F-tags and the description 63
5.1 The standard criteria for each fuguai 65
5.2 Inspection checklist for Grinding Machine (Model: BO 300A) 71
5.3 Data Collection Of Fuguai Frequency for Seven Week 72
5.4 Data of Fuguai Frequency 78
5.5 Frequency of Types of Fuguai in the Three Areas 82
5.6 Frequency of Types of Fuguai 82
5.7 Machine Condition Before and After Initial Cleaning 86
5.8 Why-why analysis for Dust 87
5.9 Why-why analysis for Coolant Spill 88
5.10 Why-why analysis for Coolant 89
5.11 Why-why analysis for Cobweb 90
5.12 Why-why analysis for Misplace Item 91
5.13 Why-why analysis for Broken Hose 92
5.14 Why-why analysis for Scratches 93
xvii
LIST OF ABBREVIATIONS, SYMBOLS, SPECIALIZED
NOMENCLATURE
A - Availability
AM - Autonomous Maintenance
Anon - Anonymous
BGSU - Bowling Green State University
CBN - Cubic Boron Nitride
dB - decibel
DVC - Diablo Valley Collage
FKP - Fakulti Kejuruteraan Pembuatan
F-tag - Fuguai Tag
JH - Jishu Hozen
JIPM - Japan Institute of Plant Maintenance
JIT - Just-In-Time
kg - kilogram
KK - Kobetsu Kaizen
kW - kilo watt
MI - Maintainability Improvement
min - minutes
mm - milimeter
MP - Maintenance Prevention
NPC - National Productivity Corporation
OEE - Overall Equipment Effectiveness
PdM - Predictive Maintenance
PE - Performance Efficiency
P-M - Planned Maintenance
PM - Preventive Maintenance
QM - Quality Maintenance
QR - Quality Rate
RCM - Reliability Cantered Maintenance
xviii
Rev - Revolution
SOP - Standard Operating Procedure
TBM - Time Based Maintenance
TPM - Total Productive Maintenance
TQM - Total Quality Management
UWM - University of Wisconsin - Milwaukee
WC - Work Centre
WCM - World Class Manufacturing
1
CHAPTER 1
INTRODUCTION
1.1 Background
Most industrial production systems are subject to deterioration with usage and age. Such
system deterioration may lead to higher production costs and lower product quality and
the increased possibility of breakdown (Wang and Hwang, 2004). Therefore, a well-
planned maintenance management program is important to reduce costly breakdowns
(Dohi et al., 2001). In some cases, system failure leads to uncountable costs, for example,
the failure of an airplane engine during flight may bring property damage and loss of life.
Therefore, extensive maintenance is necessary to improve the system availability
(Murthy and Hwang, 1996).
Total Productive Maintenance (TPM) is a proactive and cost-effective approach to
equipment maintenance which is widely adopted in Japanese industries with successful
results (Nakajima, 1988). The successful implementation of TPM depends on a number
of factors, such as a culture of mutual trust, operators agreeable to providing basic care to
their machines, and maintenance personnel trained in management and people skills
(Albert and Chan, 2000).
Tsang and Chan (2000) stated that TPM involves a restructuring of work relating to
equipment maintenance. Being relieved of such routine tasks, the expertise in the
maintenance unit can now be deployed to focus on more specialized activities such as
major repairs, overhauls, tracking and improvement of equipment performance, and
replacement or acquisition of physical assets. Instead of having to continuously fire-fight
and attend to numerous minor chores, it can now devote its resources to address strategic
issues such as formulation of maintenance strategies, establishment of maintenance
2
management information systems, tracking and introduction of new maintenance
technologies, training and development of production and maintenance workers.
Total employee involvements, autonomous maintenance, small group activities to
improve equipment reliability, maintainability and productivity, and continuous
improvement, or kaizen are the principles embraced by TPM (Tsang and Chan, 2000).
One of the main arms of TPM is Autonomous Maintenance (AM), called as Jitshu Hozen
(JH) in Japanese. The success of TPM, to a large extent, depends upon the success of
AM.
Grinding machine is extensively used in the Machine Shop Laboratory, University
Teknikal Malaysia Melaka (UTeM) to perform the task given especially in
manufacturing practice subject. The machine is exposed to the breakdown as it is not
well maintained. Maintenance and machine could not be separate to each other. Machine
needs maintenance like human needs water. Daily maintenance, although it is simple but
still could improve the effectiveness and expand the life time of the machine. This project
will provide an organized methodology to perform AM on the grinding machine.
1.2 Objectives
The aims of this project are to:
1. Perform an AM programme on the grinding machine (Model: BO 300 A).
2. Identify and analyze the abnormalities on the grinding machine (Model: BO 300
A) and the remedies.
1.3 Scope
The scope of this project is only focus on the development of AM programme. The
grinding machine (Model: BO 300 A) which is used in Machine Shop Laboratory of FKP
in UTeM is selected for the project. This project is only focused on the first three steps of
AM; initial cleaning, counter measure at the source of the problem, and cleaning and
lubrication standard (refer clause 2.6). The data is gathered from primary and secondary
3
data sources. The project is started from December 2007 until April 2008. The result of
this project may not applicable to other types of grinding machines or other machines.
1.4 Importance of Project
The importances of the project are to:
1. Promote the clean, neat and friendly workplace in FKP Machine Shop
Laboratory.
2. Reduce the accident occurs in the FKP Machine Shop Laboratory.
3. Establish an orderly shop floor where any departure from normal conditions
can be identified immediately.
4. Extends the machines life and improves availability and effectiveness.
5. Foster the development of knowledgeable students since most of the routine
maintenance tasks are carried out by themselves.
6. As a reference for academic studies related to AM.
1.5 Outline of Report
The organization of this report is as follows:
Chapter 1 is the introduction of this project, describes the background and problem
statement of the project. The objectives, scope, importance of the project and the project
outlines are also presented in this chapter.
Chapter 2 is the literature review about maintenance, describes the definition, concept
and evolution of maintenance concept and Total Productive Maintenance. Besides, the
importance of maintenance, characteristic of 8 types of maintenance and TPM are
discussed. It is also includes 8 pillars of TPM, OEE, 7 steps in developing autonomous
maintenance, and Fuguai.
4
Chapter 3 is the literature review about grinding machine (Model: BO 300A), discusses
about types of grinding machines, grinding wheels and cutting fluid. Besides, this chapter
also explain about grinding machine (Model: BO 300 A) operation, safety and the
machine troubleshooting.
Chapter 4 is the methodology, presents the appropriate methodology of this project. This
chapter includes the project process planning, flowchart, Gantt chart, data gathering
method and analytical which is includes Fuguai analysis.
Chapter 5 is the analysis and discussion, presents findings of the project. This chapter
also discussed the autonomous steps that were carried out and shows the results obtained.
Chapter 6 is the conclusion, summarizing the project work that has been done. This
chapter gives recommendation and proposes future work to improve the maintenance in
FKP Machine Shop Laboratory in UTeM.
5
CHAPTER 2
MAINTENANCE
Chapter 2 presents the literature review regarding the definition, concept and evolution of
maintenance and Total Productive Maintenance. Besides, characteristics of maintenance
with description of types and six big loses are discussed. It is also includes the literature
review regarding TPM Pillars, Overall Equipment Effectiveness, autonomous
maintenance, and fuguai.
2.1 Introduction to Maintenance
Nowadays, organizations are under great pressure to enhance continuously their
capability to create value to customers and improve the cost effectiveness of their
operations (Campbell, 1995; Duffuaa and Al-Sultan, 1997; Shenoy and Bhadury, 1998;
Tsang, 2002). In order to safeguard their performance, organizations need to formulate
viable maintenance strategies and develop a fair measure of overall effectiveness aligning
with industry's best practices (Al-Najjar, 1996).Once a system or a piece of equipment
has been purchased, it must be maintained. The decisions made at purchasing always
determine the type of future maintenance to be carried out (Levitt, 1997).
Maintenance can be define as activities intended to preserve or promptly restore the
safety, performance, reliability, and availability of plant structures, systems, and
components to ensure superior performance of their intended function when required
(Weinstein and Chung, 1999). Levitt (2005) defines maintenance as acting in the act of
holding or keeping in a preserved state of the asset to avoid the failure. Maintenance also
can be define as the combination of activities by which equipment or a system is kept in,
6
or restored to, a state in which it can perform its designated function (Duffuaa et al.,
1999).
Willmott and McCarthy (2001), state that the definition of maintenance of a Japanese
person from a world class manufacturing company as maintenance means maintaining
and improving the integrity of our production and quality system through the machine,
processes, equipment and people who add value to the products and services, that is the
operators and maintenance of the equipment. Whereas, the maintenance definition to a
typical Western manufacturing company as carry out planned servicing at fix intervals or
fix it when it break down.
Maintenance can be defined most effectively by what it does, namely, the preservation or
restoration of the desired function of a given process, at the lowest total cost (Narayan,
1998). Duffuaa et al. (1999) stated that maintenance as an integrated system that can
provide a substantial edge in organization’s ability to be competitive and provide quality
products or services. Whereas, according to Campbell et. al. (1999), maintenance is
defined by which equipment or a system is kept in, or stored to, a state in which it can
perform its designated functions.
According to Wireman (2004), maintenance is a unique business process. It requires an
approach that is different from other business processes if it is to be successfully
managed. Levitt (1997) define maintenance is war. The enemies are breakdown,
deterioration, and the consequence of all types of unplanned event. Drury (1999) describe
maintenance is a complex part of the lifetime of a dependable embedded system. Design
and maintenance must be simultaneously planned in order to ensure an efficient and cost-
effective outcome over the life of the product.