Q2. What are the key factors that affect the behaviour of operators?
For repetitive events the key contextual pressures on operators that may modify their behaviour are likely to relate to complacency and organisational issues such as excessive workloads or requirements to work at the same task too long.
Q3. What is the role of HRA in a summative analysis?
When HRA is incorporated into a summative analysis, its role is to help estimate the overallfailure probabilities in order to support decisions on, e.g., adoption, licensing or maintenance.
Q4. What is the key point that the authors have been trying to convey in this paper?
The key point that the authors have been trying to convey in this paper is the current dislocation between the mechanistic reductionist assumptions on which current HRA methodologies are primarily built and their current understandings of human and organisational behaviour.
Q5. What is the role of the organisational context in decision making?
The organisational context must be considered both as an influence on individual level decision making and as an integral outcome of individual and group decision making processes.
Q6. What are the two subjects with a great deal of overlap?
Reliability analysis and risk analysis are two subjects with a great deal of overlap (Aven 2003; Barlow and Proschan 1975; Bedford and Cooke 2001; Høyland and Rausand 1994; Melnick and Everitt 2008).
Q7. How often do the authors need to design systems with very high reliabilities?
The problem is that the authors often need to design systems with very high reliabilities, many times with overall failure rates of less than 1 in 10 million (i.e. 1 in 10-7).
Q8. What is the importance of thinking widely before making decisions?
Before decisions can be made, it is necessary to think widely, explore issues, frame the problem and develop broad strategies that are flexible enough to accommodate changes as the situation evolves.
Q9. What is the main argument for the decentralisation of the HRO?
This decentralisation may increase the complexity of the organisation as knowledge and lines of authority need to be distributed, but La Porte (1996) suggests the balance of these opposing effects can lie in the direction of higher reliability.
Q10. What is the main idea of the approach to modelling behaviour?
This approach to modelling behaviour proposed that behaviour is goal orientated and there are internal, hierarchical processes that enable people to put thoughts into actions through activation and inhibition of decision making processes (Carver and Scheier 1981).
Q11. What is the purpose of risk analysis?
When risk analysis is used formatively, its purpose is to understand better systems and identify the key drivers of risk, rather than chase quantified estimates per se.
Q12. What is the role of the decision maker in the complex space?
Decision makers will need to take probing actions and see what happens, until they can make some sort of sense of the situation, gradually drawing the context back into one of the other spaces.
Q13. What is the potential for use of HRA in the design of systems?
There would seem to be considerable potential for formative uses of HRA to influence the development of HRO theory, at least in so far as it can be applied in system and organisational design; and vice versa, complementing the work of, e.g., Grabrowski and Roberts (1999).
Q14. What is the origin of the Human Error Rate Prediction Method?
Early first generation HRA methods such as the Technique for Human Error Rate Prediction (THERP) (Swain and Guttmann 1983) were very similar to those in other areas of reliability analysis: namely, the probability of a human error is assessed via a simple event tree analysis.
Q15. What are some other methods that have similar features to THERP?
A variety of other first generation methods have been developed with broadly similar features to THERP – the use of task analysis, use of nominal probabilities for task failure, adjustment factors to take account of different performance conditions, error factors and so on.
Q16. Why did Reason suggest that systems fail because of a single failure?
Essentially this suggested that systems do not fail because of a single failure, but because several elements fail near simultaneously, as if the holes in slices of Swiss cheese have aligned.