ANALYSIS OF SAWMILL WORKERS THROUGH
INTEGRATION OF VIDEO OBSERVATION AND RULA
METHOD
MUHAMMAD JAMLI BIN MOHD ALI
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
ANALYSIS OF SAWMILL WORKERS THROUGH INTEGRATION
OF VIDEO OBSERVATION AND RULA METHOD
Thesis submitted in accordance with the requirements of Universiti Teknikal
Malaysia Melaka for the Bachelor Degree of Manufacturing Engineering in
Manufacturing Management
By
MUHAMMAD JAMLI BIN MOHD ALI
Faculty of Manufacturing Engineering
UTeM Library (Pind.1/2007)
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS PROJEK*
JUDUL: Analysis of Sawmill Workers Through Integration of Video Observation and RULA Method.
SESI PENGAJIAN: 4/2
Saya : MUHAMMAD JAMLI BIN MOHD ALI
mengaku membenarkan projek (PSM/Sarjana/Doktor Falsafah) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:
1. Projek 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 projek ini sebagai bahan pertukaran antara institusi pengajian tinggi. 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 6, Jalan Masjid, Kg Kerayong, 28200, Bera,
FAKULTI KEJURUTERAAN PEMBUATAN
- TESIS SARJANA MUDA KEJURUTERAAN PEMBUATAN (PENGURUSAN PEMBUATAN): MUHAMMAD JAMLI BIN MOHD ALI
TAJUK: ASSESSMENT OF WORKING POSTURE OF SAWMILL WORKERS THROUGH INTEGRATION OF VIDEO OBSERVATION AND RULA METHOD.
Sukacita dimaklumkan bahawa tesis yang tersebut di atas bertajuk “ASSESSMENT OF WORKING POSTURE OF SAWMILL WORKERS THROUGH INTEGRATION OF VIDEO OBSERVATION AND RULA METHOD” mohon dikelaskan sebagai terhad untuk tempoh lima (5) tahun dari tarikh surat ini memandangkan ia mempunyai nilai dan potensi untuk dikomersialkan di masa hadapan.
Sekian dimaklumkan. Terima kasih.
Karung Berkunci 1200, Ayer Keroh, 75450 Melaka
APPROVAL
This thesis submitted to the senate of UTeM and has been accepted as partial fulfillment of the requirements for the degree of Bachelor Manufacturing Engineering (Manufacturing Management) with Honours. The members of the supervisory committee are as follow:
DECLARATION
I hereby, declared this thesis entitled “Assessment of Working Posture of Sawmill Workers Through Integration Of Video Observations and RULA Method” is the results
of my own research except as cited in references.
Signature : ………
Author’s Name : Muhammad Jamli Bin Mohd Ali
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ABSTRACT
This study discusses the assessment of working posture of sawmill workers while they performing the jobs at their workstation. In sawmill industry, the workers require to perform various activities such as lifting, pulling, pushing, holding and blocking timber products. To carry out such activities, they have to perform forward bending or side bending of their body part especially the upper body. These working postures might be
negatively influencing workers’ health. In recognition the importance of working posture,
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ABSTRAK
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DEDICATION
For My Beloved Parents:
Mohd Ali bin Abu Bakar
Salmiah binti Arshad
My Beloved Siblings:
Nor Salasiah binti Mohd Ali
Noor Zaikiah binti Mohd Ali
My Respected Supervisor:
Mr Isa bin Halim
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ACKNOWLEDGEMENT
Firstly, Alhamdullillah. Thank to Allah the Almighty God S.W.T for giving me the opportunity and time to complete my thesis project for final year. Since doing this thesis, I have an opportunity to learn something new and get extra knowledge on how to conduct a project in industrial field.
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1.5 Potential Benefits of Study……….6
1.6 Outline of Study…………..………7
1.7 Report Structure ………8
2. LITERATURE REVIEW……….9
2.1 Working Posture……….……….…...9
2.1.1 Introduction to Working Posture………...9
2.2 Occupational Injuries Related to Working Posture ……….13
2.3 Laws, Rules, and Standard Related to Working Posture……….……….16
2.3.1 Laws and Rules………...……….16
2.3.2 Standards …...19
2.4 Sawmill Industry...22
2.4.1 Introduction to Sawmill Industry...22
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2.5 Recording and Measuring Working Posture Methods...28
2.6 Tools for Working Posture Analysis...30
2.6.1 Postural Analysis Tools...30
2.6.2 Computer Aided Design Software...33
2.6.3 Computer Aided Three dimensional Interactive Application...34
2.7 Previous Studies Related to Working Posture...35
3. METHODOLOGY………...40
3.1 Introduction...………..40
3.2 Phase 1: Recording and Assessment of Working Posture of Worker...…………..40
3.2.1 Recording of working posture...……….40
3.2.2 Assessment of Working Posture………...…………42
3.3 Phase 2: Redesign of Workstation to Improve Working Posture...48
3.4 Phase 3: Evaluation of The Effectiveness of Proposed Design...49
3.5 Summarization of Methodology...50
4. CASE STUDY...…...51
4.1 Background of Case Study...51
4.2 Case Study Identification...………...52
4.2.1 Factors...………...….53
4.3 Case Study 1: Working Posture during Cutting Process...55
4.4 Case Study 2: Working Posture during Arrangement of Sawn Timber...58
5. RESULTS AND DISCUSSION......………...61
5.1 Introduction...………..61
5.2 Current Workstation Design for Case Study 1...62
5.3 RULA Analysis result for Case Study 1 ...63
5.4 Current Workstation Design for Case Study 2 ...64
5.5 RULA Analysis Result for Case Study 2... 65
5.6 Redesign of Workstation Results... 66
5.6.1 Case Study 1 Result...66
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5.6.3 RULA Analysis Result for Proposal Design...69
5.6.4 Case Study 2 Results...70
5.6.5 Discussion on Three Stages Platform Design...70
5.6.6 RULA Analysis Result for Proposal Design...72
5.7 Comparison between Current Workstation Design and Improved Workstation Design...72
5.7.1 Case Study 1...73
5.7.2 Case Study 2...75
5.8 Discussion on Questionnaire and Personal Interview...76
6.0 CONCLUSION AND RECOMMENDATION...77
6.1 Record and Assessment of Working Posture...77
6.2 Redesign Current Workstation...77
6.3 Evaluation of the Effectiveness of Proposed Design...78
6.4 Recommendations...79
REFERENCES………...80
APPENDIX A
APPENDIX B
APPENDIX C
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LIST OF FIGURES
1.1 Hierarchy of study scope and focus...5
1.2 Structure of overall report...8
2.1 Sitting working posture...10
2.2 Standing working posture...10
2.3 Forward bending posture...11
2.4 Saw blades...22
2.5 Saw filers benching a double cut saw...23
2.6 Side bending posture...26
2.7 Forward bending posture...27
2.8 Excessive forward bending posture...27
3.1 Angle of working posture ...42
3.2 Angle of working posture ...42
3.3 Dimension part of anthropometric data measurement...43
3.4 RULA Analysis dialog box...45
3.5 Display button to switch the mode...47
3.6 Advance mode score display...47
3.7 Summarization of methodology ...50
4.1 Raw timbers area...52
4.2 Forklift used to transfer the raw timbers to the production site...52
4.3 Pulling posture associated with extreme manual load lifting...55
4.4 The worker has to bend to remove the timber during cutting process...57
4.5 Process flow to cut a timber...57
4.6 Install and tightening the saw blades...57
4.7 Rolling the timber to the cutter machine...57
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4.9 Worker bends to arrange sawn timbers on the platform...58
4.10 Worker twists his waist to placing the sawn timbers...58
4.11 Flow Chart of Sawn Timbers Arrangement Process...60
4.12 Take the sawn timbers from table...60
4.13 Put the sawn timber on the platform according to it dimensional size...60
4.14 Arranging the sawn timber...60
5.1 Current workstation design for Case Study 1...62
5.2 RULA Analysis Result (Right Side/Case Study 1)...63
5.3 RULA Analysis Result (Left Side/Case Study 1)...63
5.4 Current Workstation Design for Case Study...64
5.5 RULA Analysis Result (Right Side/Case Study 2)...65
5.6 Cart Design...66
5.7 Specification and proposed material of cart design...68
5.8 RULA Analysis Result (Right Side /Case Study 2)...69
5.9 RULA Analysis Result (Left Side /Case Study 2)...69
5.10 Three Stages Platform...70
5.11 RULA Analysis Result (Right Side /Case Study 1)...72
5.12 RULA Analysis Result (Left Side /Case Study 1)...72
5.13 Comparison Chart of RULA Score (Left and Right / Case Study 1)...74
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LIST OF TABLES
2.1 Accident Register Records...15
3.1 Specification of Video Camera...41
3.2 Anthropometry Data of Sawmill Workers...44
4.1 Description of Cutting Process...56
4.2 Description of Sawn Timber Arranging Process...59
5.1 Tables of RULA Analysis Score Results for Case Study 1...74
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LIST OF ABBREVIATIONS
BCPE Board of Certification for Professional Ergonomists
BLS Bureau of Labor Statistics
CAD Computer Aided Design Software
CAE Computer Aided Engineering
CAM Computer Aided Manufacturing
CMOS Complementary Metal Oxide Semiconductor
COHFE Center of Human Factor Ergonomics
CTD Cumulative Trauma Disorder
EMG Electromyography
ILO International Labour Organization
IBM International Business Machine
ISO International Organisation of Standardisation
JPEG Joint Photographic Experts Group
LBP Low Back Pain
MSD Musculoskeletal Disorder
NIOSH National Institute of Safety and Health
OSHA Occupational Safety and Health
OWAS Ovako Working Posture Analysis System
REBA Rapid Entire Body Assessment
RULA Rapid Upper Limb Assessment
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WMSD Work Related Musculoskeletal Disorder
WRULD Work Related Upper Limb Disorder
1
CHAPTER 1
INTRODUCTION
This chapter provides information regarding to background of study, problem statements, and objectives of study. Besides, this chapter also describes the scope and limitation of study, potential benefits from the study that may significant to the personal, authorities, or related organizations. The outline of conducted study also presented in this chapter
1.1 Background of Study.
Sawmill industry is an enormous industry not only in Malaysia, but also in the international level. Countries that have a wide area of forest and received a constant rain distribution per year mainly become the role player in this industry due to the unlimited source of timber plant. Currently, Malaysia is the largest exporters of logs, sawntimber, and the main exporter of wood-based product such as plywood, wooden
furniture and builders’ carpentry in Asian region. Providing a job to more than 300,000
workers, the Malaysian sawmill industry had grown rapidly and significantly play a major role to the development of socioeconomic sector in Peninsular Malaysia, Sabah and also in Sarawak (Anon, 2007a).
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lifting, pushing and removing a processed timber, handling a manual device such as saw blades, pushing trolley, and pulling a pulleys to remove the timber are the example of manual task perform by the workers repetitively and done everyday in the sawmill industry (WorkSafe, 2005).
These activities require the workers to apply a specific posture to carry out the job or can be termed as working posture. Working posture is one of the ergonomics issues under the industrial ergonomics discipline. Unsafe working posture while performing job activities not only uncomfortable to the workers, but also exposed the workers to a musculoskeletal disorders (MSD). The manual task activities perform by the workers is believed as a major contributor to the occupational injuries in the sawmill industry (Edwin M., 2003). Workers bending or twisting repetitively while performing their job associated with a great risk of MSD. MSD include sprains, strains, inflammation, degeneration, tears, pinched nerves or blood vessels, bone splintering and stress fractures. Neck, shoulder, wrist, and low back are the common body part that has a great potential to sustain injury or the MSD due to an awkward working posture such as excessive forward bending to pick up a load repetitively as what the sawmill floor workers done everyday.
3 1.2 Problem Statements.
Sawmill industry is among the manufacturing industry that applying a working environment which workers are requires to apply high forces, unsafe working posture, manual handling operations, and repetitive motions in performing job task. Unsafe working posture such as bending, twisting, pushing, and lifting a heavy load are the major contributors to the potential occupational injuries among an industrial workers. In sawmill industry, workers are highly expose to the occupational injuries due to the job activities that require them to deal with the logs and processed timber. Manual handling device and a workstation design of workers to perform their job also contribute to the occupational injuries. The design of workstation also can be a significant contributor to the workers to have a musculoskeletal disorder and other occupational injuries. It is known that work-related musculoskeletal disorders are caused by multifactor operations of various risk factors. Safe working posture is considered as vital contributor to feasible occupational health in most industries in Malaysia. Through feasible occupational health, the productivity and quality of industries can be increased. Among these, the association of these risk factors with pain symptoms and work-related musculoskeletal disorders has been reported in many studies in all typical manufacturing settings (Bernard, 1997).
Following are problems which related to the MSD injuries among the sawmill industry workers:
a) The sawmill industry is known to have a high level of manual handling, with tasks often involving high loads/forces, awkward postures, and repetitive movements; some of the key risk factors for MSDs (Tappin D. et. al, 2003). b) At least 6500 new claims occurred during the four year period of the review,
4 1.3 Objectives of Study.
In recognition the importance of working posture in sawmill industry, this study is conducted to achieve following objectives:
a) To record and assess current working posture adopted by the workers in their usual workstation.
Working postures of workers will be recorded using a video camcorder. Recorded working posture will be evaluated using Rapid Upper Limb Assessment (RULA) applied as a tool to assess the risk factors of posture, static muscle contraction, repetitive motion, and force relative to a specific job by referring to the captured image.
b) To redesign the current workstation in order to improve working posture. One of the proposed ergonomics intervention control methods which are in the scope of engineering control is applied in this study. The current workstation will be observed and redesign by using the Computer Aided Design (CAD) software which is CATIA software for this study.
c) To evaluate the effectiveness of the proposed workstation design.
5 1.4 Scope and Limitation.
Basically, this study focuses in analyzing the working posture of sawmill industry workers by applying the integration of video observation and Rapid Upper Limb Assessment (RULA) associated with CATIA v5R12. Workers of sawmill industry was selected due to their job activities that requires them to push, twist, bend, lifts, and handling with the manual device such as trolleys, thus may lead to a MSD crisis to the workers. A workstation design also will be proposed as a solution for improvement of the current working posture. The design of the proposed workstation is depend on the
company consideration as it’s only a proposed solution. The limitation for this study is
the obtained results only applicable for the selected working posture in this study and cannot be apply for other posture due to a different posture have different body part angle. This study also only concern in a physical ergonomics which focuses on biomechanical characteristic, human anatomical and physiological as it related to physical activities such as working posture that will be investigated in this study.
Figure 1.1 shows the hierarchy of focus and scope of this study:
Working
6 1.5 Potential Benefits of Study.
This study may offer potential benefits to the following parties:
a) Sawmill industry.
Able to promote and enhance ergonomics awareness in sawmill industry to
minimize occupational injuries in this industry.
The findings of the study can be used as a guideline for the industry owner to
design a workstation.
b) University or educational organizations.
As a reference for academic studies related to MSDs issue and working posture
analysis in industrial fields.
As a reference for future studies on ergonomic workstation design and
improvement of working posture of industrial workers.
c) Authorization party.
This study can be used by the National Institute for Occupational Safety and
Health (NIOSH) as a guideline and references to prevent MSD injuries among sawmill industry workers.
A document to support the effort of NIOSH in promoting a safe working
condition among the industrial workers.
d) Students.
The study may improve the students’ ability and skills in developed a case study
and enhance their soft skills.
e) Country.
