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Unformatted text preview: ERGONOMICS IN MANUFACTURING ASSOCIATE PROFESSOR DR. SITI ZAWIAH MD. DAWAL ASSOCIATE DEPT. OF ENGINEERING DESIGN AND MANUFACTURE UNIVERSITY OF MALAYA COURSE OUTCOME: COURSE Identify the importance of human factors Identify and ergonomics and safety and health in the application of equipment in work environment environment Interpret ergonomics practice in industry Design task to improve work environment Design References References 1. Ergonomics-How to design for ease and efficiency by Ergonomics-How Karl Kroemer et al-Prentice Hall 2001. Karl 2. 2. Introduction to Ergonomics by R.S. Bridger Mc Graw 2. Hill 1995. Hill 3. Human Factor in Engineering and Design by Mark S. 3. Sanders and Ernest J. McCormick – McGraw Hill 1992 Sanders 4. Work Design. Occupational Ergonomics by Konz and 4. Johnson. Holcomb Hathaway, Publishers, Inc 2004 Johnson. 5. Methods, Standards and Work Design by Benjamin 5. Niebel and Andris Freivalds McGraw Hill 2004. Niebel 6. A guide to human factors and ergonomics by Martin 6. Helander. Taylor and Francis Group LLC 2006. What are “Human Factors”? What Human Factors (ergonomics) iis the study s of helping people to work more efficiently through design of their: Tools (products) Work process Work environment Organizational structure Introduction Ergonomic is the application of scientific principles, methods and data to the development of products and systems that interact with human. interact Goals of Ergonomics Goals To increase humans’: Effectiveness Health Safety Well-being Goals of Ergonomics To generate tolerable working condition that do not pose dangers to life or health. that Acceptable conditions which people can Acceptable voluntarily agree. voluntarily To generate optimal conditions that are To well adopted to human characteristics, capability, desires that physical, mental and social well-being is achieved. and Ergonomics (European term for Human Factors)the Greek words: Factors) Ergonomics comes from ergo + nomos ergo Work Laws Companies like Human Factors not only Companies because it increases: Safety/ health/ well-being of workers Profitability But also: Human Factors: Body and Mind Human Most products today involve both: Physical components Physical Ergonomics Physical Computer component Cognitive Ergonomics Computer Designers of things and processes need Designers to understand both: to May not have HF impact on them o Need to communicate with HF experts Big need: Designers should be able to span Big disciplines/work with other disciplines o Human Factors and Ergonomics Human Human factors is the term used in the Human USA USA Ergonomics is more prevalent in Europe Ergonomics and the rest of the world and For all practical purposes the terms are For synonymous synonymous Aspect of Ergonomics Study, research and experimentation to determine human traits and characteristics for engineering design. for Application and engineering designing Application tools, machines, shelter, environment, work tasks, and job procedures to fit and accommodate to human. accommodate Focus of Ergonomics Focus Ergonomics focus on human being and Ergonomics their interaction with products, equipment, facilities, procedures and environment used in work and everyday living. used The emphasis is on human beings and The how the design of things influence people how Week 1 to Week 3- Lectures Week Week 4 – Case Study ( group work) Week 5 – Case Study ( Presentation) Week 6 – Class and Test 8 Week – Lectures 2 Tutorials will be informed later Labs - 5 Exam ( 50 % + 50% ) Exam Test ( 5% + 5%) Case Study – 20% Labs ( 20 %) Case Study - example Case Title: To redesign an “Exit Sign”. - Function of the signage - How to improve the current design How - Creative – variety of construction tools tools - situation –normal and emergency - Presentation Presentation - Report about the exit sign. Report The Report Function of exit sign Redesign model Situation – ergonomics solutions Explain about your design choices and how you applied the appropriate principles to develop the design/s. Min 5 pages max 10 pages. Ergonomics IS NOT ….. Ergonomics Applying checklist and guidelines Human factors or ergonomics is not just Human 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. common History of Ergonomics and Human Factors….. Factors….. Early history- 1900 Frank and Lillian Early 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 Hospital Based on their analysis resulted in the Based 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 The 1949 – Ergonomics Research Society 1949 (now simply called ergonomics society) was formed in Britain.) was After that the first book was published After entitled “ Applied Experimental Psychology: Human factor in Engineering Design (Chapanis, Garner and Morgan 1949) 1949) Continue…… Continue…… 1957 – journal of Ergonomics appeared 1959 – International Ergonomics 1959 Association was formed Association 1960 – 1980 – Rapid growth not just 1960 concentrate on military industrial complex. concentrate 1980 – 1990 – Computers, disasters and 1980 latigation latigation 1990 and beyond …? Important topics cover… Important Ergonomics in Design/ Work Design Anthropometry Display Design Display MSD MSD Environment Biomechanics Handtools Design Handtools Office workstations Office Ergonomics in Design Ergonomics User-oriented – age, population, etc. Human variability as a design parameter. Takes advantages of unique human Takes capabilities capabilities Build in safeguards to avoid or reduce the Build impact of unpredictable human error. impact Result Result Improved productivity. Efficiency Improve quality of life Computer Aided Ergonomics Use of man modeling systems to assess ergonomics criteria. criteria. Enable predictions of the percentage of future users who Enable may have problems with clearances, reaching, seeing or are forced to adapt unnatural or damaging postures at an early stage. an Visualisation of ergonomics problems supports efficient Visualisation communication and solution action. communication Minimize product design time scale by not requiring Minimize physical models or make-ups to be constructed. physical Basic Function of Computer Aided Ergonomics System Ergonomics 3-D modeling of people of required set, 3-D nationality, age and occupational groups. nationality, Knowledge base of comfort angle ranges and Knowledge joint movement limits to reflect actual human capabilities. capabilities. Ability to model element of workstation. Ability to assess kinematics interaction in terms Ability of user fit, reach vision etc. of Iterative modification to the design. Biomechanics evolution-joint unit of movement. Anthropometry Anthropometry Measurement of the human body Anthropometric data use ergonomics to Anthropometric 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. avoided. Anthropometry and its used Anthropometry Body size and proportion vary greatly between different Body population and racial groups-a fact which designers must never lose sight of when designing for an interna-tional market. The importance of anthropometric considerations in design as follows: design If a piece of equipment was designed to fit 90% of the male U.S. If population, it would fit roughly 90% of Germans, 80% of Frenchmen, 65% of Italians, 45% of Japanese, 25% of Thais and 10% of Vietnamese. and It is usually impracticable and expensive to design It products individually to suit the requirements of every user. user. Mass-produced and designed to fit a wide range of Mass-produced users-the custom tailor, dressmaker, and cobbler are perhaps the only remaining examples of truly userperhaps oriented designers in western industrial societies. Task of the ergonomics is : To character-ize the way a product is to be used To To identify the issues which might affect us-abilityTo iincluding the constraints which are imposed on the ncluding design by the anthropome-try of the user population. Anthropometric dimensions appropriate to the design of the particular product can be specified. The necessary data from the corresponding consumer/ The user group are obtained for use in dimensioning either user the product itself or its range(s) of adjustability. the 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 an-thropometric dimensions from data on stature. data Problems with much of the anthropometric data from the Problems United States and Europe are the age of the data and the lack of standardization across surveys. Topics Cover Topics Illumination Illumination Noise Climate Vibration Vibration Work Environment Work Measurement of light Measurement The importance of light measurement is The 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. 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. lead 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: The Note that as the wave length increases, the frequency Note 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 decibel HEARING LOSS HEARING The chances of damage to the ear, resulting in "nerve" The deafness, increase as the frequency approaches the 2,400 to 4,800 Hz range. This loss of hearing is a result of a loss of receptors in the inner ear, which then fail to transmit the sound waves further to the brain. Also, as the exposure time increases, especially where higher intensities are involved, there will eventually be an impairment in hearing. Nerve deafness is due most commonly to excess exposure to occupational noise. Individuals vary widely in their susceptibility to noise-induced deafness. susceptibility In general, noise is classified as either broadband noise or In meaningful noise. Broadband noise is made up of frequencies covering a significant part of the sound spectrum. This type of noise can be either continuous or intermittent. Meaningful noise represents distracting information that impacts the worker's efficiency. In long-term situations, broadband noise can result in deafness; in day to-day operations, it can result in reduced worker efficiency and ineffective communication. reduced TEMPERATURE TEMPERATURE Most workers are exposed to excessive heat at one time or Most 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. occurring THEORY THEORY The human is typically modeled as a cylinder with The 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 Vibration can cause detrimental effects on human performance. Vibration Vibrations of high amplitude and low frequency have especially undesirable effects on body organs and tissue. The parameters of vibration are frequency, amplitude, velocity, The acceleration, and jerk. For sinusoidal vibrations, amplitude and its derivations with respect to time are: derivations Displacement and maximum acceleration are the principal parameters used to characterize the intensity of vibration. vibration. There are three classifications of vibration exposure: 1. Circumstances in which the whole or a major portion of Circumstances the body surface is affected; for example, when highthe intensity sound in air or water excites vibration. 2. Cases in which vibrations are transmitted to the body Cases through a supporting area; for example, through the buttocks of a person driving a truck, or through the feet of a person standing by a shakeout facility in a foundry. person 3. Instances in which vibrations are applied to a localized Instances body area; for example, to the hand when holding, and operating, a power tool. operating, Protection against vibration Vibration can be reduce by modifying the speed, motion and maintaining the equipment equipment Place equipment under anti-vibration Place mounting mounting Alternating work assignment Cushion support for body vibration Bright light entering from a window Bright Solution ? Solution Monitor with a glare screen Monitor Glare from overhead light source Glare Work Design Work 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). (Das, Work design is used to distinguish design approaches which embrace issues of interdisciplinary approach, human centered approach and socio-technical approach. Job Design Job Job design refers to the way a set of Job 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. 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. motions Work Design Outputs Work Job Satisfaction Job The concept of job satisfaction has been typically defined as an has individual’s attitude about work individual’s roles and the relationship to roles worker motivation (Vroom, 1967). worker Motivation 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). Work Design Evaluation EVALUATION METHODS EVALUATION SURVEY OBSERVATION AND CHECKLIST OBSERVATION MEASUREMENTS MEASUREMENTS ANALYSE PHYSIOLOGY, WORKLOAD, AND WORK CAPACITY CAPACITY Introduction Anatomy is the study of the structure of the body and the physical relationships involved between body parts. involved Physiology is the study of how the parts of Physiology 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. of Muscle tissues and their features Muscle CUMULATIVE TRAUMA DISORDERS IN INDUSTRY INDUSTRY Cumulative trauma disorders (sometimes called repetitive motion injuries, or work-related musculoskeletal disorders) are injuries to the musculoskeletal system that develop gradually as a result of repeated microtrauma due to poor design and the excessive use of hand tools and other equipment. Because of the slow onset and relatively mild nature of the trauma, the condition is often ignored until the symptoms become chronic and more severe injury occurs. chronic Work-related musculoskeletal disorders (WMSDs) are associated with these factors: work postures and movements, repetitiveness and pace of work, force of movements, vibration, and temperature. temperature. Certain workplace conditions, for example, the layout of Certain the workstation, the speed of work (especially in conveyor-driven jobs), and the weight of the objects being handled influence these factors. EXERCISE 1 EXERCISE Figure 1 (Bending Forward) Figure Figure 2 Figure Figure 3 Figure Figure 4 Figure Figure 5 Figure Thank you !!! Thank ...
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