thinking is that when it is brought into
operation, even the most highly trained
and well-motivated personnel will make
Types, Forms, and
Taxonomies will
help designers to
ABOUT THE AUTHOR
R.B.Whittingham is an author, risk
systemic errors leading to accidents or
loss of production.
By contrast, the user-centered
approach ensures that the design of
the system is matched as closely as
possible to human capabilities and
limitations. The Blame Machine —
Why Human Error Causes
Accidents (see Resources) provides
numerous case studies of accidents
caused by designs that ignored
human capabilities. The most serious aircraft accident to occur in the
UK for many decades occurred at
Kegworth near Nottingham in 1987.
The accident resulted from an engine
instrument layout that presented
important information in a misleading way. The system may have
appeared adequate until the pilots
were faced with an emergency where
rapid decisions were called for based
on engine data from the instrument
panel. Under conditions of high
workload and stress, the mental
resources of the pilots were overstretched. This restricted their capacity to properly assimilate information
from a vibration monitor resulting in
the shutting down of the wrong
engine. Because the presentation of
that information was poor, the probability of an error was increased and
was the main cause of the accident
at Kegworth.
Unfortunately, the need to adopt
a user-centered approach is still —
even today — not fully understood by
many designers. As a result, there
are numerous examples of complex
technological systems designed
mainly with system functionality in
mind, ignoring the capabilities and
limitations of the user. Such systems
invariably result in degraded levels of
human performance with grave consequences for productivity, equipment availability, and safety.
However, the need of the engineering
designer — who is not necessarily an
expert in human factors — should
recognize how common human errors
occur. This understanding will lead to
safer and more cost
effective designs of
equipment which
take full account of
potential human
consultant, and chemical engineer with 40
years experience in plant and technical management, design engineering, and safety
consultancy in the chemical, oil and gas, railway, aviation, and nuclear industries. He has
a special interest in the role of human error
in accident causation and the use of human
error analysis to predict the likelihood and
causes of potentially dangerous errors.
also be recognized. A basic appreciation of techniques such as Task
Analysis, Human Error Analysis, and
an understanding of the various Error
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