DT4 - Exam
A2 Technology
Product Design
Systems and Control Notes
Ergonomics
What is ergonomics?
• Ergonomics is “the study of the interaction of
man and his environment”
• From the Greek ‘Ergon’ work and ‘nomos’
meaning natural laws. In other words the natural
laws of humans doing work.
• Ergonomics can be divided into the following
areas:
– Physical and Psychological ergonomics
– Cognitive ergonomics and
– Organisational ergonomics
Physical Ergonomics
• How the body responds to physical and
psychological stresses.
• For example
– ‘physical’ ergonomics means a product is
designed so that it is not too heavy, or
uncomfortable or too big or too small, or
designed to minimise this physical stresses.
This arm of ergonomics is called
ANTHROPOMETRICS.
Psychological Ergonomics
• For example
– ‘psychological’ ergonomics means a product
is designed considering how the user will
interact with it and use it. Can they
understand its use intuitively. Psychology is
the study of behaviour.
Cognitive Ergonomics
• …also known as engineering psychology,
concerns mental processes such as perception,
attention, cognition, motor control, and memory
storage and retrieval as they affect interactions
among humans and other elements of a system.
• Relevant topics include mental workload,
vigilance, decision making, skilled performance,
human error, human-computer interaction, and
training.
Organisational Ergonomics
• ... or macro ergonomics, is concerned with
the optimisation of sociotechnical systems,
including their organisational structures,
policies, and processes.
• Relevant topics include shift work,
scheduling, job satisfaction, motivational
theory, supervision, safety culture,
teamwork, telework and ethics.
Anthropometrics
• From the Greek ‘anthro’ man and ‘metrics’
measurements
• Literally means the measurement of humans.
• Today, anthropometry plays an important role in
industrial design, clothing design, and
architecture, where statistical data about the
distribution of body dimensions in the population
are used to optimize products
Anthropometrics
• Imagine you are designing a computer
desk
• You need to study the interaction of the
person with the computer (ergonomics)
and then the sizes of people who use the
desk (anthropometrics).
• Both of these pieces of information will
help you draw up a specifcation.
Anthropometrics
Anthropometric table
Female
Male
5%
50%
95%
5%
50%
95%
A
690
743
795
739
795
850
B
181
226
266
188
235
274
C
406
439
479
447
482
520
D
438
478
525
458
499
544
E
540
585
637
569
616
665
F
352
388
428
395
434
476
G
474
513
558
515
559
605
Anthropometric table
• The data was gathered by measuring
1000 or more people and recording the
frequency of each piece of data.
• A frequency graph can then be plotted for
each piece of data, for example seated
height F
• The distribution of the graph will have a
bell shaped curve which is called a normal
distribution curve.
Normal distribution curve
Frequency
Frequency graph
for seated height
F
Heights
5%
50%
95%
Normal distribution curve
Mean
Frequency
If you design for
the MEAN you
only design for
50% of the
population.
Heights
5%
50%
95%
Normal distribution curve
Frequency
Design for 90% of
the population
means your product
will be suitable for
90% of people. So
you use the 95%
percentile figure to
include in your
specification
Heights
5%
50%
95%
Normal distribution curve
Frequency
Sometimes it isn’t
possible to design for
90% of the population
as the extremes maybe
too far apart. In this
case you can design
for 50% of the
population, but
between 25th and 75th
percentile.
Heights
25%
50%
75%
Ergonome
• You can make a model of a 2D
person to help guide your
designing
• A word file has been created of a
50th percentile adult man
• Cut him out assemble him and try
him on scale drawings
• He is 1/10th full scale.
Useful sites and further reading
• http://www.ergonomics4schools.com/lzone/workspace.htm