TABLE OF CONTENTS This chapter offers some ideas for considering two additional topics in the basic risk assessment model:
Stress and human errors measurable variables that indicate a more stressful workplace, possibly leading to higher error rates
Sabotage variables to consider when the threat of intentional attacks against a pipeline facility are to be assessed.
Where either is seen to be a significant contributor to failure potential, inclusion of additional risk variables into the risk assessment might be warranted. However, for many pipelines, issues regarding operator stress levels and sabotage potential are either not significant or so uniform as to make distinctions impossible. So, either of these can be a part of the risk assessment but should be added only when the evaluator judges that its benefit exceeds the cost of the complexity that is added by its inclusion.
The incorrect operations index is largely a measure of the potential for human errors. When there is no knowledge deficiency, human error is almost exclusively caused by distraction. That is, when the person knows what to do and how to do it but inadvertently does it incorrectly, that incorrect action is the result of at least a momentary loss of focus a distraction.
Stress is a known contributor to loss of focus. Many studies have explored the relationship between stress and accidents. A general consensus is that there is indeed a strong correlation between the two. Stress can also be a beneficial condition because it creates the desire to...
