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human factor - Coggle Diagram
human factor
communication
Body language
Facial expressions , posture
Graphic
Pictures, diagrams , hand drawn sketches
Verbal
single word, phrase or sentence
Symbolic
"Thumbs up" , wave
Written
Printed text from paper or screen
social psychology
Responsibility: individual and group
If someone is considered responsible, they are liable to be called to account as being in charge or control of, or answerable for something.
responsibility should be spread across all those who play a part in the activity.
Individual responsibility
Advantage:
Will mostly do well for a given task
Disadvantage:
overlook the importance of working together as a cohesive team or group to achieve goals.
Organisational culture
It is the company own set of philosophy, policies, procedures, selection and training criteria, and quality assurance methods.
Group or team responsibility
Intergroup conflict
rivalries may arise between this team and others.
implications in terms of responsibility, with teams failing to share responsibility between them.
Group polarisation
tendency for groups to make decisions that are more extreme than the individual members’ initial positions. This is known as risky shift
Social loafing
tendency for some individuals to work less hard on a task when they believe others are working on it.
Advantage
Ownership as a group. May involve cross checking others work
Disadvantage
Diffusion of responsibility. A notion of “someone else will do it”.
May act against safety.
Motivation and de-motivation
Motivation can be thought of as a basic human drive that arouses, directs and sustains all human behaviour. Generally, we say a person is motivated if he is taking action to achieve something.
Can be affected by:
Financial bonus
Weather condition
two types of motivation
External: system rewards & punishments. Less effective compare to internal
Internal: do it because we want to.
example ; What people want from work:
o To feel valued and competent
o To feel in control (to a degree)
hazard in the workplace
Human error
Skill based errors
Slips- action not carried out as intended
Lapses - missed actions and omissions
Recognizing and avoiding hazards
Bright lights
Loud sounds
Confined areas
Working at signifigant heights
Mistakes
Misapplication of good rules
Violations
Application of bad rules
Violations
Routine violations
Situational violations
Optimising violations
Exceptional violations
factors affecting performacnce
Stress
Physical stress : Heat , noise
Social: Anxiety, incentive
Personal: Domestic issue, aches
Drugs: Alcohol, nicotine
Caffeine
Mood change
Anxiety
Insomnia
Alochol
Effects of alcohol
Visual impairment
Judgement error
slow reaction time
Sleep, fatigue and shift work
Time pressure
Workoad
Overload of work
Task priority
Working enviroment
Physical work
Social enviroment
Physical enviroment
Noise
Fumes
Illumination
Temperature
human performance and limitation
mental
memory
It is possible to distinguish between three forms of memory
working memory (short-term memory)
Auditory,
Visual-spatial
10 –30s
capacity
7 ±2 chunks
sensory memory
Echoic memory
auditory sensory memory
retained for up to two seconds.
Iconic memory
visual sensory memory,
retained only for about 0.5 second.
Haptic memory
Touch sensory memory
retained only for about 10 second
long-term memory
Semantic,
Episodic
capacity
Unlimited
Lifetime
Memory can be considered to be the storage and retention of information, experiences and knowledge, as well as the ability to retrieve this information.
Memory depends on three processes
registration - the input of information into memory;
storage - the retention of information;
retrieval - the recovery of stored information.
information processing
judement and desicion making
judement
decision making
Is the generation of alternative courses of action based on available information, knowledge, prior experience, expectation, context, goals, etc. and selecting one preferred option. It is also described as thinking, problem solving and judgment.
attention and perception
perception
transforming data into information
requires existing knowledge and experience to know what data to keep and what to discard, and how to associate the data in a meaningful manner.
Attention
influenced by arousal level and stress
types of attention
Selective -attention cannot be focused on more than one thing at a time. It has alimited capacity.
Divided -is concentration on more than one thing (for example, listening to two people speaking at once).
Focused -Focused attention is the state of concentrating on one stimulus to the exclusion of all others.
Sustained -"the ability to direct and focus cognitive activity on specific stimuli." In order to complete any cognitively planned activity, any sequenced action, or any thought one must usesustained attention.
Attention and perception shortcomings
Can impinge on decision making
Depending on Human memory to make decision is fallible as information
may not be stored;
• may be stored incorrectly;
• may be difficult to retrieve
Forgetting is when information is not available (not stored in the first place) or inaccessible (cannot be retrieved).
To avoid forgetting
Use manual
Use temporary aide-memoires
confirmation bias
Once we have formed a mental model of a situation, we often seek information which will confirm this model and, not consciously, reject information which suggests that this model is incorrect.
situation Awareness
Situation awareness is the synthesis of an accurate and up-to-date ‘mental model’ of one’s environment and state, and the ability to use this to make predictions of possible future states.
In Maintenance engineering context, it refers to
the perception of important elements, e.g. seeing loose bolts or missing parts, hearing information passed verbally;
the comprehension of their meaning, e.g. why is it like this? Is this how it should be?
the projection of their status into the future, e.g. future effects on safety, schedule, airworthiness.
To improve situational awareness
feedback - informing us of the accuracy of our mental models and their predictive power
project system status backward - determine what events may have led to an observed system state, as it allows effective fault finding and diagnostic behaviour.
Claustrophobia, physical access and other phobias
Physical access and claustrophobia
Claustrophobia can be defined as abnormal fear of being in an enclosed space.
Work in team to assist one another making allowances for the fact that people come in all shapes and sizes and that it may be easier for one person to access a space, than another.
Aware of fellow colleagues if they may difficulty in working in enclosed space
Fear of heights
it is very important that appropriate use is made of harnesses and safety ropes.
Avoid such task if it can affect safety
physical
hearing
performance and limitation of the ear
impact of noise on performace
be annoying (e.g. sudden sounds, constant loud sound, etc.);
• interfere with verbal communication between individuals in the workplace;
• cause accidents by masking warning signals or messages;
• be fatiguing and affect concentration, decision making, etc.;
• damage workers’ hearing (either temporarily or permanently).
The audible frequency range that a young person can hear is typically between 20 and 20,000 cycles per second (or Hertz),with greatest sensitivity at about 3000 Hz.
components of the ear
middle ear
transmits vibrations from the eardrum by way of three small bones known as the ossicles,
protect the ear from sounds above 80 dB by means of the acoustic or aural reflex, reducing the noise level by up to 20 dB.
inner ear
This contains a fine membrane (the basilar membrane) covered in hair-like cells transmits vibration to the brain via the auditory nerve
outer ear
The outer part of the ear directs sounds down the auditory canal, and on to the eardrum.
hearing impairment
temporary loss
caused by relatively short exposure to very loud sound
Can last from a few seconds to a few days
Additional exposure may lead to permanent hearing loss
permanent loss
Regular exposure to high levels of noise over a long period
noise levels
85 decibles
assess the risk to employees’ hearing
tell the employees about the risks and what precautions are proposed
Provide ear protection and explain their use
90 decibles
Reduce expose to noise
Mark zone where noise reach 2nd level
and provide sign to restrict entry
140 decibles
noise causes pain
high and low tone deafness
Normal human hearing range is 20 Hz to 20000Hz
This is very important when measuring noise since two sounds of equal intensity, but of different frequencies, may appear subjectively to be of different loudness.
Deterioration of the sensory hairs occurs with over exposure to high levels of noise
Long hair sensory; which detect low frequencies
Short hair sensory; which detect high frequencies.
hearing protection
It is good practice to reduce noise levels at source, or move noise away from workers.
Hearing protection should always be used for noise, of any duration, above 115 dB
presbycusis
When one grows old, hearing deteriorates and it affects the ability to hear high pitch sound first. When this natural decline is exacerbated by noise induced hearing loss, it can obviously occur rather sooner.
vision
colour vision
colour loss at night
The reason for night myopia lies in the differing frequency of colours
that prevail by night, and the varying ability of the eyes lens to focus
them.
Good color vision for maintenance engineers is important for
recognizing components;
• distinguishing between wires;
• using various diagnostic tools;
• recognizing various lights on the airfield (e.g. warning lights).
visual acuity
limiting factors of the visual acuity of the eye
Physical factors
influence of ingested foreign substances
Environmental factors
Factors associated with object being viewed
Other visual problems
Is the ability of the eye to discriminate sharp detail at varying distances
blind spot
Occurs at the point where the optic nerve enters the retina
(between the rods and cones).
common eye defects
Short sight (near-sight) - known as myopia
Eyeball is longer than normal
image to be formed in front of the retina
Distance object are blurred
A concave lens overcomes short sightedness by bending light
outwards before it reaches the cornea
Long sight (far sight) - known as hypermetropia, or hyperopia
Eyeball is shorter than normal
image is formed behind the retina
Blurred vision will result when looking at close objects
A convex lens overcomes long sightedness by bending light
inwards before it reaches the cornea.
anatomy of the eye
the lens
Shape is changed by the muscles (cillary muscles) surrounding it
Final focusing adjustment to place a sharp image onto the retina
The change of shape of the lens is called accommodation
Can be affected by factors such as fatigue or the ageing process
iris and pupil
Coloured part of the eye
Controls the amount of light that is allowed to enter the eye
the retina
Contain 2 types of sensitive cells
cones
capable of detecting fine detail and are colour sensitive
Function in good light
Located at the Fovea
rod
Located in periphery of the retina
cannot detect colour
poor at distinguishing fine detail
sensitive at lower light levels
Made up of a complex layer of nerve cells connected to the optic nerve
Central area of the retina is known as the fovea
cornea
Clear ‘window’ at the very front of the eye.
Acts as a fixed focusing device.
Responsible for 70% to 80% of light total focusing ability