Page 220 - Pipeline Risk Management Manual Ideas, Techniques, and Resources

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Additional Risk
Modules

This chapter offers some ideas for considering two additional deficiency, human error is almost exclusively caused by dis-
topics in the basic risk assessment model: traction. That is, when the person knows what to do and how
to do it but inadvertently does it incorrectly, that incorrect
Stress and human errors-measurable variables that indicate a action is the result of at least a momentary loss of focus-a
more stressful workplace, possibly leading to higher error rates distraction.
Sabotag+variables to consider when the threat of inten- Stress is a known contributor to loss of focus. Many studies
tional attacks against a pipeline facility are to be assessed. have explored the relationship between stress and accidents.
A general consensus is that there is indeed a strong correlation
Where either is seen to be a significant contributor to failure between the two. Stress can also be a beneficial condition
potential, inclusion of additional risk variables into the risk because it creates the desire to change something. Some
assessment might be warranted. However, for many pipelines, experts therefore make a distinction between positive and nega-
issues regarding operator stress levels and sabotage potential tive stress. For purposes of this discussion, the focus will be on
are either not significant or so uniform as to make distinctions negative stress-that set of human reactions that has a poten-
impossible. So, either of these can be a part of the risk assess- tially destructive effect on health and safety.
ment but should be added only when the evaluator judges that Stress is a highly subjective phenomenon in that equal exter-
its benefit exceeds the cost ofthe complexity that is added by its nal conditions do not initiate equal stress states among all peo-
inclusion. ple. It is not the external conditionthat causes the stress, it is the
manner in which the external condition is viewed by an individ-
1. Stress and human errors ual that determines the reaction. More and more, stress is being
viewed as a matter of personal choice, indicating that people
Background can control their reaction to external stimulus to a greater
degree than was previously thought. Nonetheless, experience
The incorrect operations index is largely a measure of the shows that certain external stimuli can be consistently linked
potential for human errors. When there is no knowledge with higher stress states in many individuals.