Abstract
Quantitative risk assessment may be integrated by means of human reliability analysis, which assesses the probability of human failure events by evaluating the influence of underlying factors on human performance. A step-by-step tutorial for the application of a human error quantification technique is presented in this chapter. However, the application of this technique should be preceded by a thorough qualitative analysis of the tasks performed by the operator/crew in the scenario considered. As an example of application, the analysis of a scenario of drive-off of a semisubmersible drilling unit is studied. This demonstrates how to account for issues of human–machine interface, stress, shortage of time, and rare-event experience, which may lead the operator into failure and increase the probability of an accident.