Just Culture decision tree for determining the culpability of unsafe acts by James Reason (1997)
1. Introduction
The Decision tree to determine the culpability of unsafe acts was created by Professor James Reason, School of psychological science, Manchester University – UK . Professor Reason spent more than 25 years of research on human error management and system errors in numerous high risk industries such as aviation, nuclear power, transportation and healthcare.
In order to decide whether a particular behaviour is culpable enough to require disciplinary action, a policy is required to decide fairly on a case-by-case basis. Reason’s Culpability Decision Tree follows, representing a structured approach for determining culpability. The assumption is that the actions under scrutiny have contributed to an accident or to a serious incident. There are likely to be a number of different unsafe acts that contributed to the accident or incident, and Reason believes that the decision tree should be applied separately to each of them. The concern is with individual unsafe acts committed by either single person or by different people at various points of the event sequence.
The 5 stages include:
- Intended act: The first question in the decision tree related to intention. If both actions and consequences are intended, it is possibly criminal behaviour and should be dealt with outside of the company.
- Under the influence of alcohol or drugs: Known to impair performance at the time that the error was committed. A distinction is made between substance abuse with or without ‘reasonable purpose’, which is still not blameless, but not as serious as taking drugs for recreational purposes.
- Deliberate violation of rules: did the system promote the violation or discourage the violation; or had the behaviour become automatic or part of the ‘local working practices’.
- Substitution test: could a different person (equally motivated, competent and qualified) have made the same error under similar circumstances (determined by peers). If ‘yes’, the person who made the error is likely to be blameless. If ‘no’, were there system-induced reasons (insufficient training or positioned) ? If not, negligent behaviour should be considered.
- Repetitive errors: The final question asks whether the person has committed unsafe acts before. This does NOT presume culpability, but may imply that additional training or counseling is required.
*Reason’s Foresight test: Provides a prior test to the substitution test above, in which culpability is thought to be dependent on the kind of behaviour the person was engaged in at the time: Did the individual knowingly engage in behaviour that an average operator would recognise as being likely to increase the probability of making a safety critical error ? If the answer to this question is “Yes” in any of the following circumstances, the individual is culpable. However, even in cases of situations below, there may be reasonable causes, and as such the Substitution test still needs to be utilized for accurate assessment of events:
- Performing duties while under influence of drugs or substances that may reduce productivity.
- Making jokes, not being serious while performing duties.
- On duty while being fatigued due to having worked multiple shifts in a row.
- Using below standard or inappropriate equipment to perform duties.