I- Introduction to Ergo

Healthy life in the work

environment

Ergonomics

Outline

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What is Ergonomics? Brief History of Ergonomics Simple and Complex Work systems Description of Human-Machine Systems Modern Ergonomics Anatomy, Posture & Body Posture Anthropometric principles in workspace &

Equipment design Workspace design for standing & seated workers

Outline

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The Upper Body at workDesign of manual handling taskIndustrial application of PhysiologyHeat, Cold & design of the physical environmentVision, light & lightingHearing, sound and noiseHuman Information processing, skill & performanceDisplay, controls & human machine InteractionMemory, language and the design of verbal material

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Cognitive ergonomics, problem solving & decisionmakingErgonomics, work organization and work system

design

Book: Introduction to ergonomics 2nd Edition R.S Bridges (any Ergonomics book)

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Introduction to Ergonomics

Objectives:

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Understand the concept of ergonomics and what it’s not.

Identify the simple and complex work system.

Establish relationship between human, machine and environment.

Define the modern contribution of ergonomics to systems design and management.

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“Ergonomics”• Ergon = work• Nomos = laws• “the laws of work”

Alternative Names• Humans Factors Engineering• Human Engineering• Occupational Psychology• Engineering Psychology• Applied Experimental Psychology

What is Ergonomics?

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Ergonomics Ergonomics is the study and optimization of the interaction

between people and their physical environment by considering their physical, physiological, and psychological characteristics.

Is concerned with the design of systems in which people carry out work.

Is the applied science that fits jobs to people by designing tasks, equipment, and tools to work optimally with individual human characteristics.

Ergonomics is the process of fitting the job to the worker — instead of the worker to the job.

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Occupational Ergonomics

. Concerns the application of ergonomics principles specifically to the workplace and related tasks.

Purpose :

1. To eliminate or, if not practicable, minimize the risk of musculoskeletal injury to employees.

2. To provide solutions to work related pain and discomfort.

3. Enhanced productivity.

4. Saves money.

Two distinct Aspects;

1. Study, research and experiment.

2. Application and Engineering.

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Factors Causing Ergonomics Injuries -- Ergonomic injuries may be caused by:

. Lifting and handling heavy objects

. Twisting with load

. Working in awkward postures

. Reaching far forward or far behind

. Repeating movements

. Working with a bent wrist

. Gripping high force

. Working in cold temperature conditions

. Working with vibrating tools

. Sitting, standing, or holding an object in the same position for a long time

. Working with tools that put direct pressure on body parts

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Signs and Symptoms The most common signs and

symptoms of musculoskeletal illnesses or injuries include:

. pain. numbness . tingling. weakness . swelling. whitening of the fingers at cold

temperature. reduced range of movement

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Ergonomic Controls

• Engineering

–Modify the tool or work area design

• Administrative

–Don’t do one thing too long

• Work Practices

–Use the right tool

Six Pillars of Ergonomic Design “Wisdom”

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User Orientation: Design and application of tools, procedures, and systems must be user-oriented, rather than just “task” oriented

Diversity: Recognition of diversity in human capabilities and limitations, rather than “stereotyping” workers/users

Effect on Humans: Tools, procedures, and systems are not “inert”, but do influence human behaviour and well-being

Six Pillars of Ergonomic Design “Wisdom”

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Objective Data: Empirical information and evaluation is key in design process, rather than just use of “common sense”

Scientific Method: test and retest hypothesis with real data, rather than “anecdotal” evidence or “good estimates”

Systems: object, procedures, environments, and people are interconnected, affect one another, and do not exist in “isolation”

Costs of Ignoring Ergonomics

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Less production output Increase lost timeHigher medical costHigher material cost Increase absenteeismLow quality work Injuries, strains Increase probability of accidents and errors

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What Ergonomics is NOT

1. NOT just applying “universal” checklists and guidelines blindly

2. NOT using oneself as the model for design since there is diversity and variation

3. NOT just using common sense since must be based on real data and information

Requirements for effective participation

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Employees should have to;> acknowledge the need for participation.> trust that their participation will not have negative

effects & they will have some control over the final decision.

> perceive that changes are being introduced in a legitimate way.

> believe that change are being implemented correctly> be given a real role to play in the introduction and

testing of new ways of working.

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Work system

• are purposeful, goal-directed systems which produce a clearly identifiable output for a previously defined output.

•The output of worksystem may arise directly from the machine or directly from the human component.

•The scope of ergonomics is extremely wide and is not limited to any particular industry or application

Simple and Complex Worksystem

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SIMPLE ERGOSYSTEMS

COMPLEX ERGOSYSTEMS

A B

CD

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M

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A> Improving System Performance and Reliability

the purpose of ergonomics is to enable worksystem to function better by improving the interactions between the human component and the other components

there is technical tendency to seek technical means of improving system performance and blame accidents and breakdowns on “human error”.

Important factors to be investigated are the following :


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A> Improving System Performance and Reliability

1. Design of system components, particularly human-machine interfaces.

2. State of the system leading up to the incident (e.g, stable/unstable, quiet/busy, on course/off course, etc.)

3. Operator’s mental and physical workload.

4. Work Organization ( e.g, shift system, supervision, design of work groups)

5. External factors ( e, g, weather )


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B> Ergonomics in Practice

The practice of ergonomics require that knowledge about human anatomy, physiology, and psychology be applied to work systems.

Two ways in which ergonomics has an impact upon systems design in practice:

1. Ergonomist work in research organizations and universities and carry out basic research to discover characteristics of people that need to be allowed for in design.

2. They work in consultancy capacity either privately or in an organization.

Simple and Complex Work system

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•Ergonomics is a multidisciplinary subject and in order for it to be applied in a consistent and coherent way, a model or framework is required which specifies its areas of application, boundaries and limitations.

Description of Human-Machine Systems

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Interaction DESIGN ISSUE

Display-workspace Location of DisplaysDisplay-environment Effects of lighting, vibration, noise on legibilitySenses-workspace Sensory access to taskSenses-environment Environmental requirements for operation of the sensesProcessing-environment Effects on perception and cognitionProcessing-organization Skill levels,training,fatigue,motivationEffectors-workspace Determination of workspace envelopeEffectors-environment Effects on vibration and climate on effectorsControls-workspace Task description needed to optimize control layoutControls-environment Effects of environment on usability of controls

Adapted from Leamon (1980)

COMMON INTERACTIONS BETWEEN THE COMPONENTS OF A WORKSYSTEM

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A> The Human Components of a Worksystem

•The human body is part of the physical world and obeys the same physical laws as other animate and inanimate objects.

•The human body is consist of a jointed skeleton, muscles, connective tissues, sense organs, and an information-processing center-the brain.

•It is important to distinguish between the effectors and the senses themselves and the physiological and psychological processes which support and sustain working behaviours.

•The 3 primary effectors are the hands, the feet and the voice. They are the mechanisms by which information is entered into a machine or passed from one human to another.


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A> The Human Components of a Worksystem

• The senses are means by which we are made aware of our surrounding. Five senses - sight, hearing, touch, taste and smell.

•The supportive processes. The human component requires energy and information in order to carry out work and activities.


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B> Machine Components of a Worksystem

Machine is used in a general sense to include any manufactured device which augments some aspect of human behaviour.

1. Controlled Process - basic operation of the machine on its local environment as controlled by human.

2. Displays -in simple worksystems, this is often just the action of the machine on its local environment. The process is its own display.

3. Controls- human interaction with machines depends on the provision of suitable controls which can be acted on by the effectors.


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C> The Local Environment

The term is used to describe the place and the circumstances in which work is carried out and consists of physical workspace, the physical environment, and the social and technical constraints under which the work is done.

1. Workspace -three-dimensional space in which work is carried out.

2. The Physical Environment -the worksystems approach points to those which have an influence on the way human and machine components interact.

3. Work Organizations - refers to the immediate organization of human-machine interaction. Refers to the organizational structure in which the work activity is embedded, the technical system, and the social system which supports it.


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Modern Ergonomics•Modern ergonomics contributes to the design and evaluation of worksystems and products.

• Design is a team effort nowadays.

• The Ergonomist plays an important role at both the conceptual phase and in detailed design as well as in prototyping and the evaluation ofexisting products and facilities.

• Modern ergonomics contributes in a number of ways to the design of the worksystem. These activities should be seen as an integralpart of the design and the management of systems rather than as“optional extras.”

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CONTRIBUTION OF MODERN ERGONOMICS IN SYSTEMSDESIGN AND MANAGEMENT

1.A standard format for describing human-machine systems.- Can be used to generate checklist and methodologies for evaluating prototypes or existing systems. - The two most important first steps when using the human-machine model are to describe the technology and to describe the user or operator.- A major task of the ergonomist is to describe the human at all levels appropriate to the particular system.

2. Identification, classification, and resolution of designs issues involving the human component.- identify the design issues which involve the human component of the work system and to classify them in order to render them amenable to further analysis using appropriate knowledge.- HUMAN BEHAVIOR AT WORK TAKES PLACE IN THE CONTEXT OF A SYSTEM AND IS SHAPED BY THE WAY THE SYSTEM IS DESIGNED.

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3. Task and human-machine interaction analysis.

-Tasks can be analyzed by breaking them down into various components and subcomponents in a structured way to reveal the behavior required of the human and the context in which the behavior takes place in the worksystem.

-Task analysis provides a system-specific context for the application of the fundamental ergonomic principles.

- Some ways of analyzing tasks are hierarchical representation of tasks behaviors, observational techniques for obtaining data about the behavior involved in carrying out a task, and methods for representing the dynamic aspects of human-machine interaction. The outcome of task analysis consists of the following:

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1. A description of the behaviors required to carry out the task.2. A description of the system states which occur when task is carried out.3. A mapping of the task behavior onto the system states.

-This information can be used for a variety of purposes:1. Evaluation or the design of the human-machine interface.2. Identification of the skills needed by an operator of the system3. Design of training materials and operating instructions.4. Identification of critical elements of the task to predict or evaluate the reliability of the system.

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4. Specification of system design and human behavior. Implementation of controls.

- The ergonomist must be able to specify. appropriate human behaviors and actions in the operation of a system

5. Identification of core trends in human and biological science and their implications for system design and management

- An important role for ergonomics generally and for the ergonomist working in a large organization is to act as an interface between developments in basic human and biological sciences and organizational needs.- Information is usually of a general nature and cannot always be used in straightforward “cookbook” fashion.

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6. Generation of new concepts for the design and analysis of human-machine systems.

The design of human machine interface is the classical point of departure for the application of ergonomics. One way of prioritizing recommendations is as follows :

1.Implement recommendation immediately (e.g.,there is serious design flaw threatening the employee health or system reliability)

2. Implement recommendation soon (e.g., the current way of working is un satisfactory, but there is no immediate danger)

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3. Implement when equipment is shut down (e.g., if stoppages are expensive and there is no immediate danger, wait until the system is shut down for regular maintenance or repair and then implement the idea)

4,. Implement when cost-benefit ratio is acceptable (e.g., wait until financial situation improves or implementation costs are lower)

5. Implement when equipment is built or purchased (e.g.,phase in new products or items on a replacement basis as old ones are discarded.

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7. Evaluation of Socio-technical implications of design options.

-The design of new systems and the redesign of existing ones can have serious implications for the organizational climate.

- Technological and organizational changes can have profound effects on the working lives of individuals, and it is the part of ergonomist’s function to determine what these effects might be and to anticipate future problems.

Sources Used

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Chaffin et al., Occupational Biomechanics, 1999.

Frankel and Nordin, Basic Biomechanics of the Skeletal System, 1980

Sanders and McCormick, Human Factors in Engineering and Design, 1993.

Moore and Andrews, Ergonomics for Mechanical Design, MECH 495 Course Notes, Queens Univ., Kingston, Canada, 1997.

R.S. Bridger, Introduction to Ergonomics, 1995

The end…The end…

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Prepare for a short Quiz…

Exercise 1Exercise 1

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Give at least 3 examples of the factors causing Ergonomics Injuries that you encounter in your everyday activity in school. What are the sign and symptoms of illnesses or injuries and your propose solutions.

I- Introduction to Ergo

Documents

complex worksystemagt

machine systemsagt

improving

machine interaction

local environment

real data

environment

work system