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INDUSTRIAL ERGONOMICS KCEP 4103. DR. SITI ZAWIAH MD. DAWAL DEPT. OF ENGINEERING DESIGN AND MANUFACTURE UNIVERSITY OF MALAYA. References. 1. Ergonomics-How to design for ease and efficiency by Karl Kroemer et al-Prentice Hall 2001
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INDUSTRIAL ERGONOMICS KCEP 4103 DR. SITI ZAWIAH MD. DAWAL DEPT. OF ENGINEERING DESIGN AND MANUFACTURE UNIVERSITY OF MALAYA
References 1. Ergonomics-How to design for ease and efficiency by Karl Kroemer et al-Prentice Hall 2001 2. Introduction to human Body by Gerard J. Tortora and Sandra Reynolds Grabowski. Wiley 2001 (Physilogy) 3. Introduction to Ergonomics by R.S. Bridger Mc Graw Hill 1995. 4. Human Factor in Engineering and Design by Mark S. Sanders and Ernest J. McCormick – McGraw Hill 1992 5. Engineering Physiology by K.H.E.Kroemer- International Thomson Publishing- Van Nostrand Reinhold 1997 6. Work Design. Occupational Ergonomics by Konz and Johnson. Holcomb Hathaway, Publishers, Inc 2004 7. Fisiologi Manusia by A. Raman, Ruby Husin, M.Afandi Muhamad. Kursus Pengajian Tinggi Fajar Bakti - 2000.
Week 1 to Week 3- Lectures • Week 4 – Case Study ( Survey) • Week 5 – Case Study ( Presentation) • Week 6 – 7 Lectures • 2 Tutorials will be informed later • Labs- 6 – 8 labs
Exam ( 60 % - 30% + 30%) • Test ( 5%) • Case Study – 15% • Labs ( ~ 10 % - 20 %)
Case Study • Title: Investigation on MSD,mental fatigue and back-pain at workplace . - Choose appropriate Questionnaire - work method and organization - Posture Observation - Effect on health and productivity - Ergonomics solution - Presentation * Back-pain on nurses.
Introduction • Ergonomics is the application of scientific principles, methods and data to the development of products and systems that interact with human.
Human Factors and Ergonomics • Human factors is the term used in the USA • Ergonomics is more prevalent in Europe and the rest of the world • For all practical purposes the terms are synonymous
Goals in Ergonomics • To generate tolerable working condition that do not pose dangers to life or health. • Acceptable conditions which people can voluntarily agree. • To generate optimal conditions that are well adopted to human characteristics, capability, desires that physical, mental and social well-being is achieved.
Aspect of Ergonomics • Study, research and experimentation to determine human traits and characteristics for engineering design. • Application and engineering designing tools, machines, shelter, environment, work tasks, and job procedures to fit and accommodate to human.
Focus of Ergonomics • Ergonomics focus on human being and their interaction with products, equipment, facilities, procedures and environment used in work and everyday living. • The emphasis is on human beings and how the design of things influence people
Ergonomics IS NOT ….. • Applying checklist and guidelines • Human factors or ergonomics is not just common sense. To some extent use of common sense would improve a design but ergonomics is more than just that. Example selecting an audible warning that can be heard and distinguished from alarms is not determined by simple common sense.
History of Ergonomics and Human Factors….. • Early history- 1900 Frank and Lillian Gilbreth began their work in motion study and shop management. Their work can be considered as one of the forerunners to what was later to be called “ Human Factors”. Their work the study of skilled performance and fatigue and the design of work stations and the equipment for the handicapped.
Hospital surgical team • Based on their analysis resulted in the procedure used today. For example a surgeon obtains an instrument by calling for it and extending his hand to a nurse who places the instrument in the proper orientation. • Prior to the Gilbreth’s work, surgeons pick up their own instruments from a tray.
The Birth of a profession • 1949 – Ergonomics Research Society (now simply called ergonomics society) was formed in Britain.) • After that the first book was published entitled “ Applied Experimental Psychology: Human factor in Engineering Design (Chapanis, Garner and Morgan 1949)
Continue…… • 1957 – journal of Ergonomics appeared • 1959 – International Ergonomics Association was formed • 1960 – 1980 – Rapid growth not just concentrate on military industrial complex. • 1980 – 1990 – Computers, disasters and latigation • 1990 and beyond …?
Important topics cover… • Ergonomics in Design • Anthropometry principles • Computer (Office) Workstation design • Selection and design and arrangement of controls and displays
Ergonomics in Design • User-oriented – age, population, etc. • Human variability as a design parameter. • Takes advantages of unique human capabilities • Build in safeguards to avoid or reduce the impact of unpredictable human error.
Result • Improved productivity. • Efficiency • Safety and health • Improve job satisfaction • Improve quality of life
Computer Aided Ergonomics • Use of man modeling systems to assess ergonomics criteria. • Enable predictions of the percentage of future users who may have problems with clearances, reaching, seeing or are forced to adapt unnatural or damaging postures at an early stage. • Visualisation of ergonomics problems supports efficient communication and solution action. • Minimize product design time scale by not requiring physical models or make-ups to be constructed.
Basic Function of Computer Aided Ergonomics System • 3-D modeling of people of required set, nationality, age and occupational groups. • Knowledge base of comfort angle ranges and joint movement limits to reflect actual human capabilities. • Ability to model element of workstation. • Ability to assess kinematics interaction in terms of user fit, reach vision etc. • Iterative modification to the design. • Biomechanics evolution-joint unit of movement.
Anthropometry • Measurement of the human body • Anthropometric data use ergonomics to specify physical dimensions of workspaces, equipment, furniture and clothing so as “to fit the task to the man” and to ensure physical mismatches are avoided.
Anthropometry and its used • Body size and proportion vary greatly between different population and racial groups-a fact which designers must never lose sight of when designing for an international market. • The importance of anthropometric considerations in design as follows: • If a piece of equipment was designed to fit 90% of the male U.S. population, it would fit roughly 90% of Germans, 80% of Frenchmen, 65% of Italians, 45% of Japanese, 25% of Thais and 10% of Vietnamese. • It is usually impracticable and expensive to design products individually to suit the requirements of every user. • Mass-produced and designed to fit a wide range of users-the custom tailor, dressmaker, and cobbler are perhaps the only remaining examples of truly user-oriented designers in western industrial societies.
Availability of Anthropometric Data • Anthropometry of military populations is usually well documented and is used in the design of everything from cockpits to ranges and sizes of boots and clothing. • Data are available for U.S., British, and other European groups, as well as Japanese citizens. • Pheasant (1986) provides a useful and well illustrated collection of anthropometric data and a method of estimating unknown anthropometric dimensions from data on stature. • Problems with much of the anthropometric data from the United States and Europe are the age of the data and the lack of standardization across surveys.
Topics Cover • Illumination • Noise • Climate • Vibration
Measurement of light • The importance of light measurement is essential in the design and evaluation of workplace • Because our eyes adapts to light levels, automatically compensating for any changes in illumination, therefore subjective estimates of the amount of light in a work area are likely to be misleading.
Potential Hazard Bright lights shining on the display screen "wash out" images, making it difficult to clearly see your work. Straining to view objects on the screen can lead to eye fatigue.
Recommended Illumination Levels for Use in Interior Lighting Design
NOISE • Sound waves originate from the vibration of some object, which in turns sets up a succession of compression and expansion waves through the transporting medium (air, water, and so on). • Thus, sound can be transmitted not only through air and liquids, but also through solids, such as machine tool structures. • Sound can be defined in terms of the frequencies that determine its tone and quality, along with the amplitudes that determine its intensity. Frequencies audible to the human ear range from approximately 20 to 20,000 cycles per second, commonly called Hertz and abbreviated Hz.
The fundamental equation of wave propagation is: • Note that as the wave length increases, the frequency decreases. Methods analysts measure sound intensity with a sound-level meter; the unit of sound intensity is the decibel (dB). The greater the amplitude of the sound waves, the greater the sound pressure, measured on the decibel scale
TEMPERATURE Most workers are exposed to excessive heat at one time or another. In many situations, artificially hot climates are created by the demands of the particular industry. Miners are subjected to hot working conditions due to the increase of temperature with depth, as well as a lack of ventilation. Textile workers are subjected to the hot, humid conditions needed for weaving cloth. Steel, coke, and aluminum workers are subject to intense radiative loads from open hearth furnaces and refractory ovens. Such conditions, while present for only a limited part of the day, may exceed the climatic stress found in the most extreme, naturally occurring climates.
THEORY The human is typically modeled as a cylinder with a shell, corresponding to the skin, surface tissues, and limbs, and with a core, corresponding to the deeper tissues of the trunk and head. Core temperatures exhibit a narrow range around a normal value of 98.6° F (37 C). At values between 100-102° F (37.8-38.9° C), physiological performance drops sharply. At temperatures above 105° F (40.6° C), the sweating mechanism may fail, resulting in a rapid rise in core temperature and eventual death.
VIBRATION Vibration can cause detrimental effects on human performance. Vibrations of high amplitude and low frequency have especially undesirable effects on body organs and tissue. The parameters ofvibration are frequency, amplitude, velocity, acceleration, and jerk. For sinusoidal vibrations, amplitude and its derivations with respect to time are:
Protection against vibration • Vibration can be reduce by modifying the speed, motion and maintaining the equipment • Place equipment under anti-vibration mounting • Alternating work assignment • Cushion support for body vibration
Work Design • Industrial work design can be described as the specification of work content, method and relationships to satisfy the requirement of the worker and the system (Das, 1999). • Work design is used to distinguish design approaches which embrace issues of interdisciplinary approach, human centered approach and socio-technical approach.
Job Design • Job design refers to the way a set of task or entire job is organized. It is used especially in enrichment and enlargement type of activity or job characteristics or content with work context.
Workplace Design • Concentrates on dealing with the workstation, the tools and the body position that influence the way a person does his or her work. Good workplace design reduces static positions, repetitive motions and awkward body positions.
Job Satisfaction The concept of job satisfaction has been typically defined as an individual’s attitude about work roles and the relationship to worker motivation (Vroom, 1967).
Motivation • Various authors have defined motivation differences as the psychological process that gives behavior purpose and direction (Kreitner, 1995); an internal drive to satisfy an unsatisfied need (Higgins, 1994); and the will to achieve (Bedeian, 1993).
EVALUATION METHODS • SURVEY • OBSERVATION AND CHECKLIST • MEASUREMENTS
Introduction • Anatomy is the study of the structure of the body and the physical relationships involved between body parts. • Physiology is the study of how the parts of the body work, and the ways in which they cooperate together to maintain life and health of the individual.
Skeletal muscular anatomy is divided into ergonomically important “subassemblies” of the spine, the upper extremity and the lower extremity and also the components of joints, tendons, muscle and nerves.