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ECH5507Human Behaviour and Human

Error in Engineering

Human Factors Engineering and Ergonomics

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“Safety is, without doubt, the most crucial investment

we can make. And the question is not what it costs

us, but what it saves.”Robert E. McKee, Chairman and Managing Director, Conoco (UK)

Ltd.

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In a midwestern factory, an assembly-line worker had to reach to an awkward location and position a heavy component for assembly. Toward the end of a shift, after grabbing the component, he felt a twinge of pain in his lower back. A trip to the doctor revealed that the worker had suffered a ruptured disc, and he missed several days of work. He filed a lawsuit against the company for requiring physical action that endangered the lower back

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Examining a bottle of prescription medicine, an elderly woman was unable to read the tiny print of the dosage instructions or even the red-printed safety warning beneath it. Ironically, a second difficulty prevented her from potentially encountering harm caused by the first difficulty. She was unable to exert the combination of fine motor coordination and strength necessary to remove the “childproof” cap.

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In a hurry to get a phone message to a business, an unfortunate customer found herself “talking” to an uncooperative automated voice response system. After impatiently listening to a long menu of options, she accidentally pressed the number of the wrong option and now has no clue as to how to get back to the option she wanted, other thank to hang up and repeat the lengthy process.

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In the Persian Gulf in 1987, the USS Vincennes, a U.S. Navy cruiser, was on patrol in the volatile, conflict-ridden Persian Gulf when it received ambiguous information regarding an approaching aircraft. Characteristics of the radar system displays on board made it difficult for the crew to determine whether it was climbing or descending. Incorrectly diagnosing that the aircraft was descending, the crew tentatively identified it as a hostile approaching fighter. A combination of the short time to act in potentially life-threatening circumstances, further breakdowns in communication between people (both onboard the sihp and from the aircraft), and crew expectancies that were driven by the hostile environment conspired to produce the captain’s decision to fire at the approaching aircraft.

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Tragically, the aircraft was actually an Iranian passenger airline, which had

been climbing rather than descending.

Wickens et. al., An Introduction to Human Factors Engineering.

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ERGONOMICSA Greek Term

ERGON --> WORKNOMOS --> LAW

The Laws to be Observed at Work

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• The science of fitting the task and working environment to the worker

• Adoption of the job and workplace to the worker by designing tasks depending upon:– Worker’s capabilities– limitations

Introduction

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• Ergonomics is concerned with the ‘fit’ between people and their work

• It takes account of the worker’s capabilities and limitations in seeking to ensure that tasks, equipment, information and the environment suit each worker

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• Approach used is to obtain an effective match and optimize between

worker work system• Benefits:– Work efficiency– Safety and health– Comfort and easy of use– Job satisfaction

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Human

Work environmentMachine

Ergonomics

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Few Aspects of Ergonomics

safety, comfort, ease

Safety – medicine bottles: the print on them could be larger so that a sick person who may have bad vision (due to sinuses, etc) can more easily see the dosages and label

Ergonomics: could design the print style, color and size for optimal viewing

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Comfort – alarm clock display: some displays are harshly bright, drawing one’s eye to the light when surroundings are dark

Ergonomics: could re-design this based on contrast principles

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Ease of use – street signs: sometimes it is difficult to spot street signs

Ergonomics: could be addressed with the principles of visual detection in ergonomics

Watch: Ergonomia

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2 Main Domains of ErgonomicsPhysical ergonomics is concerned with human anatomical

and anthropometric as they relate to physical activityRelevant topics include working postures, materials handling and

repetitive movements

Cognitive ergonomics is concerned with mental processes, such as memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system

Relevant topics include mental workload, decision-making, human-computer interaction, human reliability and work stress as these may relate to human-system design

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Work Risk FactorsCertain characteristics of the work setting have been associated with injury. These work characteristics are

called risk factors and include:

Physical task characteristics (primarily interaction between the worker and the work setting)

Posture, force, repetition

Environmental characteristics (primarily interaction between the worker and the work environment)Heat stress, cold stress, lighting, noise

Hazard in Work Place

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ChemicalDustsGasesFume

PhysicalNoise

RadiationTemperature

Lighting

BiologicalBacteriaVirusesMouldsFungi

MechanicalFallingImpact

ElectricalElectrostatic

Direct contact

PsychosocialShiftsStress

Job scope

ErgonomicRepetitive work

Load liftingStanding

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• To decrease risk of injury/illness• To enhance workers’ productivity• To improve quality of work life

What are the purposes of ergonomics in work place?

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Why Ergonomics is Important?Kim Vicente, a University of Toronto Professor of Ergonomics, argues that the nuclear disaster in Chernobyl is attributable to plant designers not paying enough attention to human factors.

Cognitive Ergonomics“The operators were trained but the complexity of the reactor and the control panels nevertheless outstripped their ability to grasp what they were seeing (during the prelude to the disaster).”

The Human Factor: Revolutionizing the Way People Live with Technology, Kim J. Vicente

Ergonomists study human capabilities in relationship to work demands. Proper ergonomic design is necessary to prevent repetitive strain injuries, which can develop over time and can lead to long-term disability.

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OSHA 1994 and FMA 1967

• Relevant provisions in OSHA 1994 and FMA 1967

• Relevant guidelines to ergonomics

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Provisions of OSHA 1994• Section 4c:

“To promote an occupational environment for persons at work which is adapted to their physiological and psychological needs”

The third object intends to promote a suitable work environment that fulfills the needs of persons at work. It is intended to fit the process and workstation to the physiological and psychological needs of the employees. The work environment should be conducive to human physiology e.g working in hot environment would require appropriate rest-work regime; trolley to assist carrying of heavy weights above individuals capacity. It should also meet psychological needs of the employees e.g employee should not be overwork or underwork; an appropriate level of stressor that maximize productivity but not resulting an employee who is stressed. Sexual harassment can be considered as a psychosocial hazard in the work place.

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• Section 15 Duty of employer on safety, health & welfare at work of all his employees.

• Section 4c)“To promote an occupational environment which is adapted to the physiological and psychological need of workers”

Provisions of OSHA 1994

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FMA 1967 and It’s Regulations

• Section 10 – provision relating to safety– Safe access

“such means as are reasonably practicable shall be provided, maintained, and used so as to ensure safe access to any place at which any person has at any time to work”

• Section 12– No person shall be employed to lift load so heavy

so as to cause bodily injury to him

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Manual Handling

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• Section 24 – Personal Protective Clothing“Provide suitable and adequate personal protective clothing and appliances including where necessary goggles, gloves, leggings, caps, foot-wear and protective ointment or lotion.”

FMA 1967 and It’s Regulations

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Guidelines Guidelines related to ergonomics

• Guidelines on Occupational Safety and Health in the Office 1996– This guideline outlines minimum standards for the Occupational

Safety and Health for workers in the office• Guidelines on Occupational Safety and Health for Standing

at Work 2002• Guidelines on Occupational Safety and Health for Seating at

Work 2002. These guidelines explain how suitable seating contributes to the safety and health of people at work, for example by helping to prevent back pain

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• Guidelines of Occupational Safety and Health for Working with Video Display Units (VDU’s) 2003– This booklet provides explanation of questions that are

most commonly asked about VDUs and it also suggests simple adjustment that can be made to the workplace to make it more comfortable and minimized

• Guidelines on Occupational Vibration 2003• The guidance is not mandatory and employers and self-

employed persons are free to choose other ways and means of complying with the provision of the Occupational Safety and Health Act, 1994. Nevertheless, adoption of these guidelines will likely go a long way towards compliance with this Act.

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Class Assignment

• Pick a topic of interest related to ergonomics (possibly solutions to a problem).

• Read at least 5 papers on the chosen topics.• Discuss via a 15 minutes presentation in class

and a report write up.• Presentation is scheduled on Wednesday, Feb

23rd, 2011.