Acronyms & Terms Glossary

Human Reliability Analysis (HRA)

A structured approach used to identify potential human failure events and to systematically estimate the probability of those events using data, models, or expert judgment. Human Factor Analyses provide qualitative insight to the human factors issues related to the error, and also provide a more accurate quantitative assessment than is found in standard LOPA tables for human performance credits. The ability to model conditional dependence among operator tasks, as well as model potential human recovery factors from errors, makes the HRA a valuable tool. For a typical HRA, a standard operating procedure (SOP) is broken down into discrete tasks. Interviews with Operations are conducted, known as a ""talk-through,"" as well as a plant ""walk-through"" which covers the equipment of concern from the SOP. PSFs (Performance Shaping Factors) related to each task are discovered. Dependencies among tasks are estimated. Each of these will influence the HEP (Human Error Probability) for each task. Each task is to be modelled as a success or failure. An HRA Event Tree is constructed, each identified task being a branch in the tree, and then solved; the output of which is typically an input to a QRA.

aeSolutions has the Human Factors Reliability Experts to handle this task.