Please Wait...


PT Notes

Cognitive Biases in PHA

PT Notes is a series of topical technical notes on process safety provided periodically by Primatech for your benefit. Please feel free to provide feedback.

Many decisions are made by process hazard analysis (PHA) teams in identifying hazard scenarios and determining if there is a need for measures to reduce the risk of catastrophic accidents. People may be expected to make important decisions rationally. However, cognitive processes can operate to impede rationality. People tend to make decisions based on cognitive factors rather than factual evidence and cognitive biases occur.

Cognitive biases are unconscious, automatic influences on human judgment and decision making that can cause reasoning errors; distort perceptions, interpretations, and judgments; and produce irrational decisions. They arise from various mental processes, including information-processing shortcuts, and motivational and social factors. Many cognitive biases have been documented and their nature and causes described. Cognitive biases occur commonly.

This body of knowledge can be used to understand and try to avoid erroneous decisions by PHA teams. For example, humans have evolved heuristics, or mental shortcuts, that govern judgment and decision making. People employ heuristics subconsciously and are unaware of their use. Unfortunately, erroneous decisions can result in some situations. For example, the anchoring, availability, and representative heuristics can come into play during PHA studies and affect study results adversely. Other cognitive biases such as groupthink, group polarization, mindsets, peer pressure, and satisficing also can influence the decisions of PHA teams.

PHA facilitators must understand the impact of cognitive biases and other psychological factors on PHA studies because they can seriously impact the quality of study results. Hazard scenarios may be missed, risks estimated incorrectly, and important recommendations omitted. The effect of cognitive biases can be minimized by following appropriate guidelines. For example, use of a devil’s advocate as a PHA team member can address many cognitive biases. A devil's advocate challenges and debates views offered by others in order to help determine their validity. Devil’s advocates actually may agree with the views offered but their role is to challenge them, possibly even by taking an opposing position.

This subject was addressed in a recent article that provides further guidelines for dealing with cognitive biases:

Cognitive biases in process hazard analysis, Journal of Loss Prevention in the Process Industries, DOI: 10.1016/j.jlp.2016.06.014.

The article can be accessed for free on ScienceDirect until November 1, 2016 by clicking on the link below. No sign up or registration is needed.


You may contact Primatech for further information by clicking here.

To comment on this PT Note, click here.

Back to PT Notes