Introduction to Health and Safety at Work

Introduction to Health and Safety at Work
56
to ensure that personnel selection procedures should 
match people to the job. This will reduce the possibility 
of accidents or other incidents.
4.5 
Human errors and violations
Human failures in health and safety are either classi-
fi ed as errors or violations. An error is an unintentional 
deviation from an accepted standard, while a violation is 
a deliberate deviation from the standard (see Figure 4.7).
4.5.1 Human 
errors
Human errors fall into three groups – slips, lapses and 
mistakes, which can be further sub-divided into rule-
based and knowledge-based mistakes.
Slips and lapses
These are very similar in that they are caused by 
a momentary memory loss often due to lack of attention 
or loss of concentration. They are not related to levels 
of training, experience or motivation and they can usu-
ally be reduced by re-designing the job or equipment or 
minimizing distractions.
Slips are failures to carry out the correct actions 
of a task. Examples include the use of the incorrect 
switch, reading the wrong dial or selecting the incorrect 
component for an assembly. A slip also describes an 
action taken too early or too late within a given working 
procedure.
Lapses are failures to carry out particular actions 
which may form part of a working procedure. A fork lift 
truck driver leaving the keys in the ignition lock of his 
truck is an example of a lapse as is the failure to replace 
the petrol cap on a car after fi lling it with petrol. Lapses 
Slips of
action
Lapses of
memory
Rule-based
mistakes
Knowledge-
based
mistakes
Routine
Situational
Exceptional
Violations
Human
failures
Errors
Skill-based
errors
Mistakes
Figure 4.7
Types of human failure.

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