UNIVERSITI TEKNIKAL MALAYSIA MELAKA
EVALUATION OF PRODUCT ASSEMBLABILITY USING
LUCAS HULL METHOD
Thesis submitted in accordance with the requirements of Universiti Teknikal
Malaysia Melaka for the Bachelor Degree of Manufacturing Engineering in
Manufacturing Management
By
NURAZHANI BIN ABAS
Faculty of Manufacturing Engineering
May 2008
UTeM Library (Pind.1/2007)
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS TESIS*
JUDUL: EVALUATION OF PRODUCT ASSEMBLABILITY USING LUCAS HULL METHOD
SESI PENGAJIAN : 2007/2008
Saya NURAZHANI BIN ABAS
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)
Disahkan oleh:
(TANDATANGAN PENULIS)
Alamat Tetap: LOT 1635 LRG. JUARA 1D TAMAN SUKMA, PETRA JAYA 93050 KUCHING SARAWAK.
Tarikh: 02 MEI 2008
(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.
DECLARATION
I hereby, declared this thesis entitled “Evaluation of product assemblability using Lucas
Hull method” is the results of my own research except as cited in the references.
Signature
Author‟s Name
Date
:
:
:
……………………..
Nurazhani bin Abas
2nd May 2008
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 (Management). The members of the supervisory committee are as follow:
…………………………………………
Mr. Nik Mohd Farid Che Zainal Abidin
(PSM Supervisor)
Official stamp: ………………………..
Date : ………………………..
ABSTRACT
This report was provided to explain the result of study on the evaluation of product
assemblability using Lucas Hull method. The focused on Lucas Hull Design for
Assembly (DFA) method that used as a guideline for design assembly product. This study
covers the importance, benefits, limitations and any related issues that occurred in Lucas
Hull DFA method. The data was obtained from several techniques and methodologies
such as further study on DFA tool, analysis product and implemented evaluation using
TeamSet software. The TeamSet software provides result of product assemblability. In
addition, based on result, several components of product was redesign to improve the
product assemblability.
i
ABSTRAK
Laporan ini disediakan bagi menerangkan keputusan berkenaan kajian penilaian
keupayaan cantuman produk berdasarkan teknik Lucas Hull. Tumpuan terhadap teknik
rekabentuk untuk cantuman Lucas Hull yang digunakan sebagai tatacara untuk
rekabentuk produk cantuman. Kajian ini meliputi kepentingan, kelebihan, had dan
berkenaan isu yang terdapat pada teknik rekabentuk untuk cantuman Lucas Hull. Data
diperolehi dari teknik dan tatacara seperti belajar dengan lebih lanjut mengenai
rekabentuk untuk camtuman, produk analisis dan mengaplikasikan penilaian
menggunakan perisian ‟TeamSet‟. Keputusan penilaian keupayaan cantuman produk
diperolehi dari perisian ini. Tambahan pula, berdasarkan keputusan, beberapa komponen
dari produk akan direka semula untuk menaiktarafkan keupayaan cantuman produk
tersebut.
ii
DEDICATION
Firstly, thank to Allah S.W.T for the opportunity to finish this project. I owe this project
and my true happiness to my beloved parent. Since the day I started joining this
University until today, they are very caring and supporting for me.
For my adored parents:
Abas bin Tomik
Temah binti Abang
And for my respected sisters:
Nurazah Aishah binti Abas
Nurazierah Athirah binti Abas
iii
ACKNOWLEDGEMENT
Assalamualaikum warahmatullahi wabarakatuh.
First and foremost, Alhamdulillah, thank God for giving me a chance to complete my
Final Year Project. I would also like to thank my beloved parents Abas bin Tomik and
Temah binti Abang, my siblings and my friends especially Nurul Anis Nadia bt Zahar for
giving me their support and motivation during my good and hard times.
Thank you to all UTeM lecturers and staffs involved in this project especially my
supervisor, En. Nik Mohd Farid Che Zainal Abidin. Not forgetting all technicians at
UTeM that had been helpful in providing information needed to make this project a
success. Without all of you, I could not have achieved what I have today.
Last but not least, my special thanks to all of my colleagues that always giving assist for
me to finish this research. Without all of you, I would not be where I‟m today. Thank you
again.
Thank you. Wassalam.
Nurazhani bin Abas
iv
TABLE OF CONTENTS
Abstract .............................................................................................................................. i
Abstrak .............................................................................................................................. ii
Dedication ........................................................................................................................ iii
Acknowledgement ........................................................................................................... iv
Table of Contents .............................................................................................................. v
List of Figure.................................................................................................................... ix
List of Table ..................................................................................................................... xi
List of Abbreviations ...................................................................................................... xii
1. INTRODUCTION..................................................................................................... 1
1.1. Background Introduction ..................................................................................... 1
1.2. Problem Statement ............................................................................................... 2
1.3. Objectives ............................................................................................................ 3
1.4. Scope of Study ..................................................................................................... 3
1.5. Benefit of Study ................................................................................................... 3
1.6. Report Outline ..................................................................................................... 4
2. LITERATURE REVIEW ........................................................................................ 5
2.1. Introduction.......................................................................................................... 5
2.2. History ................................................................................................................. 6
2.3. Assembly ............................................................................................................. 7
2.3.1. Assembly Method ..................................................................................... 8
2.3.2. Manual Assembly ..................................................................................... 8
2.3.3. Hard Automation Assembly ................................................................... 11
v
2.3.4. Robotic Assembly ................................................................................... 11
2.4. Design for Manufacture and Assembly (DFMA ............................................... 12
2.5. Guideline of DMFA ........................................................................................... 13
2.5.1. Simplify and Reduce Number of Parts ................................................... 13
2.5.2. Standardize and Use Common Parts and Material ................................. 14
2.5.3. Design for Fabrication ............................................................................ 14
2.5.4. Process Capability................................................................................... 15
2.5.5. Mistake-proof product design assembly ................................................ 16
2.5.6. Orientation and Handling ........................................................................ 16
2.5.7. Interconnections and Flexible Parts ........................................................ 17
2.5.8. Design for Ease Assembly ...................................................................... 18
2.5.9. Joining and Fastening ............................................................................. 18
2.5.10. Modular Product ..................................................................................... 18
2.5.11. Automated Production ............................................................................ 19
2.6. Design for Assembly (DFA ............................................................................... 19
2.6.1. Methodology of DFA .............................................................................. 20
2.7. Design for Manufacture ..................................................................................... 20
2.7.1..Methodology of DFM……………………………………………………21
2.8. Boothroyd Method ............................................................................................. 21
2.9. Hitachi Method .................................................................................................. 21
2.10. Lucas Hull Method .......................................................................................... 22
2.10.1. Theory of Lucas Hull Method................................................................. 22
2.10.2. Evaluation Procedure .............................................................................. 22
2.11. Assemblability Analysis .................................................................................. 25
2.11.1. Assemblability Factor ............................................................................. 26
2.12. TeamSet Software ............................................................................................ 26
2.12.1. Design for Assembly............................................................................... 27
2.12.1.1. DFA Methodology ......................................................................... 28
2.12.1.2. Functional Analysis ....................................................................... 28
2.12.1.3. Handling Analysis .......................................................................... 29
vi
2.12.2. Assembly Sequence Flowchart (ASF) .................................................... 30
2.12.3. Manufacturing Analysis .......................................................................... 31
2.12.4. Design to Target Cost (DTC ................................................................... 32
2.12.5. Failure Mode Effect Analysis (FMEA) .................................................. 33
2.12.6. Quality Function Deployment (QFD) ..................................................... 33
2.12.7. Concept Convergence ............................................................................. 34
3. METHODOLOGY ................................................................................................. 35
3.1. Introduction........................................................................................................ 35
3.2. Methodology Flowchart of Project .................................................................... 36
3.3. Analysis Product ................................................................................................ 38
3.4. Evaluation Assemblability ................................................................................. 39
3.4.1. Procedure of DFA ................................................................................... 39
3.5. Design Improvement ......................................................................................... 40
3.6. Evaluation of Design Improvement ................................................................... 40
4. RESULT AND DISCUSSION ............................................................................... 41
4.1 Introduction ......................................................................................................... 41
4.2 Analysis of product ............................................................................................. 42
4.3 Assembling feature ............................................................................................. 47
4.4 Result .................................................................................................................. 49
4.4.1
4.4.2
Assembly Sequence Flowchart ............................................................... 49
Evaluation Result .................................................................................... 51
4.4.2.1 Result Analysis ................................................................................. 51
4.4.3 Analysis Summary .................................................................................. 55
4.5 Design Improvement ........................................................................................... 56
4.5.1 Redesign .................................................................................................. 56
4.5.1.1 Snap fit .............................................................................................. 56
4.5.1.2 Eliminate Parts .................................................................................. 57
4.5.2
4.5.3
Evaluation ............................................................................................... 58
Result analysis ........................................................................................ 59
vii
4.5.4 DFA Analysis Summary ......................................................................... 61
4.6 Result Comparison .............................................................................................. 61
4.7 Discussion ........................................................................................................... 63
4.7.1
4.7.2
4.7.3
4.7.4
4.7.5
Initial Design ........................................................................................... 63
Analysis on Assembly............................................................................. 64
Product Design ........................................................................................ 64
Efficiency Factor ..................................................................................... 66
Manual Insertion and Fastening .............................................................. 69
4.7.5.1 Fastening Choice ............................................................................... 69
5. CONCLUSION ....................................................................................................... 72
5.1 Introduction ......................................................................................................... 72
5.2 Result .................................................................................................................. 72
5.3 Recommendation ................................................................................................ 73
5.3.1
5.3.2
Product Design ........................................................................................ 68
Teamset Software.................................................................................... 74
5.4 Further Study ...................................................................................................... 74
REFERENCES .............................................................................................................. 75
APPENDICES
A
B
Gantt Chart for PSM I
Gantt Chart for PSM II
viii
LIST OF FIGURE
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
2.14
2.15
Main schema of OPM
Entities in CPM
Geometrical features in part handling
Other features affecting parts handling
Incorrect geometry can allow part to jam during insertion
Relative costs of different assembly method
Production ranges for each type of assembly method
Examples of design features affecting assembly
DFA flowchart
Example of PBS
Part Assembly Window
Functional analysis window
Handling analysis window
Primary process in manufacturing analysis
Materials selection for manufacturing analysis
6
7
9
10
10
11
12
13
23
27
28
29
30
31
32
3.1a
3.1b
3.2
3.3
3.4
Methodology flowchart for PSM I
Methodology flowchart for PSM II
Example of product assembly
Liaison diagram
TeamSet window; DFA icon choose
36
37
38
39
40
4.1
4.2
Product structure
Screw fastening area
46
47
ix
4.3
4.4
4.5a
4.5b
4.6
4.7a
4.7b
4.8
4.9a
4.9b
4.10
4.11a
4.11b
4.12
4.13
4.14
Snap fit area
Self locating area
Design for assembly flowchart for initial iron dry design
Design for assembly flowchart for initial iron dry design
Analysis result for initial design of iron dry
Potential improve area
Potential improve area
Potential eliminate part
Design for assembly flowchart for new design of iron dry
Design for assembly flowchart for new design of iron dry
Analysis result for new design of iron dry
Effect of part thickness on handling time
Effect of part size on handling time
Rearrangement of connected items to improve assembly efficiency and reduce costs Holding down and combination factor
Parts that thickness and small in size
48
48
49
50
55
56
57
58
59
59
61
67
67
68
68
69
x
LIST OF TABLE
2.1
2.2
2.3
2.4
Lucas DFA method- Manual Handling Analysis
Lucas DFA method- Manual Fitting Analysis
Toolkits in TeamSet software
Symbol in ASF
24
24
26
30
4.1
4.2
4.3
4.4
4.5
4.6
4.7
Components of iron dry
Group of components and fastening process
Assembly problem
Group of components and fastening process for new iron dry design
Result comparison
Design change
Advantages and disadvantages of different kinds of fastening technique
42
52
53
60
62
62
70
xi
LIST OF ABBREVIATIONS
AEM
ASF
Con-Con
CPM
CSM
DFA
DFM
DFMA
DTC
FMEA
MA
OAM
PBS
PDM
PSM
QFD
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Assembly Evaluation Method
Assembly Sequence Flowchart
Controlled Concept Convergence
Core Product Model
Component Supplier Management
Design for Assembly
Design for Manufacture
Design for Manufacture Assembly
Design to Target Cost
Failure Mode Effect Analysis
Manufacturing Analysis
Open Assembly Model
Product Breakdown Structure
Product Data Management
Projek Sarjana Muda
Quality Function Deployment
xii
CHAPTER 1
INTRODUCTION
1.1 Background Introduction
Manufacturing industry is one of the fields that play an important role in gaining a profit
for country. It is also important in evolution of technology for human kind.
Manufacturing is being studied hundred of years ago. Many achievements have been
done regarding manufacturing field. In manufacturing, there were many processes that
involved. One of the process was assembling. Assembly was an old process that does
manually by human at ancient time. Time by time, assembly process evolved so more
efficient and reducing time of production. Nowadays, assembly is done manually by
human and automatically by robot.
Assembling part is one of important process in manufacturing. Final assembly is the
moment of truth (Charles H. Fine, MIT) (Whitney, 2004). Although this process is
infamous but it is process that human always do. Assembling part play a major role in
manufacturing field. Assembly is to bring or come together or to fit or put together. In
manufacturing, assemble means putting two or more parts together to make one product.
The product must be functioning to use by human. Assembling parts also involved
efficiency and time. The part that easily to assembled can reduce time and may lead to
make mass production. This easily assemble also can reduce assemble cost.
1
A method that known as Design for Assembly (DFA) was proposed to help designers
considered assembly problem. Design for assembly is a process by which products are
designed with ease of assembly in mind. Most products are assembled manually and the
DFA method for manual assembly is the most widely used. Each product has their own
assembleability than to determine weather the product good in assembly or not.
The development of DFA has lead to development of Design for Manufacture (DFM).
DFM is design that considered for manufacture. The DFA and DFM have strong
relationship that gives benefit to manufacturing field. The manufacturing field has faced
many challenges and the survival in this field is by used effectives tools and
infrastructure. The uses of DFA and DFA have been made widely and these tools have
lead to increasing in new design development.
1.2 Problem Statement
Nowadays, one of the major processes in manufacturing field was assembling parts.
Many companies that involved manufacturing want to reduce cost of their product make
mass production and increase quality and reliability of the product. In assembling the
product, there is opportunity for defective component and an assembly challenge. Delay
in components assembly and miscommunication with manufacturers can lead to delays
and cost overruns. Many ways to reduce the cost have taken such as reduce time
assembling and simplified assembling process. Tolerance accumulation becomes more
significant and may require additional design and manufacturing to produce an
acceptable assembly.
2
1.3 Objectives
1. To identify improvements on product assemblability using Lucas-Hull method
2. To evaluate product assemblability using Lucas-Hull DFMA software.
3. To redesign the product and re-evaluate its assemblability using Lucas-Hull
method.
4. To identify process in assembling parts of the product.
5. To compared product assemblability before and after improvement.
1.4 Scope
In this project, parts of the product will be identified and analyzed. Assemblability of the
product will be evaluated. Evaluation of the product is using Lucas-Hull DFMA software.
This evaluation is used to redesign and improved product structure. Redesign is on part of
product and this will lead to redesign the product itself. It is also to compare product
assemblability before and after improvement. All the process of assembling parts that
regarding for this project is discuss in this project.
1.5 Benefit of study
In this project, there are many benefit and advantages can get from this study. The
knowledge that gains from this project is useful in manufacturing industry field. The
benefits that get from this study are:
a. Gain more and further knowledge about manufacturing process especially
assembling process.
b. Can enhance in using software that regarding assembling process.
c. Able to generate idea and can solve problem that occur in the project.
d. Enable to analyze product and may able to outcome new design of product.
e. The result or finding from this study can be implementing by industry to improve
manufacturing activities.
f. As a reference for future study.
3
1.6 Report outline
This report are consist five chapters. Chapter 1 generally about introduction of project
which covers the assembly process and tools that used in this project. This chapter also
includes problem statement, objectives, scope of study, benefits of study, report outline
and report structure. Chapter 2 is discussing about literature review where theory and
further knowledge are included in this chapter. Further about assembly process and tools
that used is discuss in this chapter. Software used for this project will also be described in
this chapter. Chapter 3 is about methodology in doing this project. The method that use is
analysis, evaluating using software, improvement and outcome solution.
In chapter 4, the data that collected are analyzed. The data will be evaluated and
recorded. In this chapter also mentioned the result from analysis and evaluation result.
This chapter also includes the proposing in improvement of product. The discussion
about whole project is discussed in this chapter. Lastly in chapter 5, it is conclusion about
project. This chapter will summarize all about this project and benefit that gain from the
project.
4
Chapter 2
LITERATURE REVIEW
2.1 Introduction
This chapter will discuss about assembly process, tools of assembly and TeamSet
software that use in this project. Study and research has been done to gain better
knowledge regarding to this project. Further knowledge that gets from study and research
is used as guidance to enable proceeds with the project. The project is based on product
assembly and features in the assembly to make the assembly process easy to handle. In
assembly, the method of assembly and type of assembly are mention and analysis of
assembly doing during early stages. This to ensure potential problem can identify that
may affect product performance. Designer must know the difficulty of assemblability and
know weather the part can be assembled or not.
The assemblability and analysis can be made by evaluating assembly. Assembly
evaluation is to recognize design quality for assemblability or feasibility. Assembly
evaluation is very important to gather information regarding assemble and feature of
assemble. The information is very important because it is can used as a key to improving
design quality for better assemblability. The information also can use as a guide for
further research in assembly process. There are many way for assembly evaluation. There
are many model and tools that are used in making the evaluation. The model and tools are
developing to make the application assembly process used to make manufacture product
design for a better quality. One of the tools that used was Lucas Hull method. Teamset
software that based on Lucas Hull method can used to evaluate product assemblability.
5
2.2 History
The first guideline that widely used for assembly in manufacturing is Design for
Assembly (DFA). Design for Assembly is develop by Boothroyd and Dewhurst in 1989.
This guideline has resulted in several automated assembly evaluation and advisory
system. The DFA is earlier tools that used regarding assemble product. Then this pioneer
tool has encouraged to development of other tools and model. The other tools of DFA are
Lucas Hull method. Nowadays many other tools and model had been develop as a feature
to face nowadays challenge in manufacturing field especially assemble product. The
developing of model is to unify and integrate product or assembly information. The new
model that develops to support tools of assembly such as Core Product Model (CPM) and
Open Assembly Model (OAM). The model overview all aspect in assembling from parts
to process of assembled. This overview can help to analyzed product assemble more
easy. To make the tools easy to used, software regarding tools are develop.
Figure 2.1: Main schema of OPM
Source: Zha, Foufou, Sudarsan and Sriram, (2004)
6
Figure 2.2: Entities in CPM
Source: Zha, Foufou, Sudarsan and Sriram, (2004)
The software will help the designer to applied tools of assembly easier and more
effective. In this project, the software that used is TeamSet software that based on Lucas
Hull method. The software is used to evaluate product assemblability and measure the
performance regarding assembling of product. TeamSet is a software package which
helps designers produce better products at minimum cost and in shorter time. This
software has been used widely to applied DFA tool. Toolkits that include in this software
are Quality Function Deployment (QFD), Manufacturing Analysis (MA), Failure Mode
Effects Analysis (FMEA), Design to Target Cost (DTC) and Controlled Concept
Convergence (Con-Con).
2.3 Assembly
Assembly is process that combine one or more parts to other parts to make product.
Process of assembly is old process that used by manufacturer to make product. Assembly
is an important process because it is last process to make functional product. Beside that,
assembly can influence cost to manufacture of product. Many guideline about assemble
have been develop to ensure quality of product and at the same time can reduce cost to
7
manufacture the product. Process of assembly involved many method and process
capability. At ancient time, human used this process manually and supported by using
tools. Nowadays, assembly can be doing using robot and it is do automatically.
2.3.1 Assembly method
There are three major methods in the process of assembly. This method was widely
applied in the industrial field. These three methods were effectively used and
manufacturer usually used only one or two method at the same time. Each of the method
has its own advantages and disadvantages. The major method was manual assembly, hard
automation assembly and robotic assembly.
2.3.2 Manual assembly
This is the old and ancient process of assembly. Although it was an old method, but it
still widely used by certain manufacturer or company to assemble component. This
manual assembly is handled manually by human. This kind of method based on human
skill and human support by tool to manual assembly. Good assembly of product is
because of skillful handling by human. Unskillful of this process can lead to low quality
product. This method also usually takes more time. This manual assembly still chooses
by manufacturer as a method to assembly because it is low cost.
In manual assembly, there are many processes that involved making assemble to possible
to maintain and good of assembling product can be made. The design product that to be
assembled must be analyzed of it parts to detect the criteria of assembling. To joining two
parts, there is many ways that can be made but the best ways must be choose to ensure
the parts can be join easily and problem of joining can be avoid. The manual assembly
can be dividing to two major processes which are handling the assembly and insertion
and fastening of assembly.
8