## 2 Theoretical Frameworks
### HRO Principles  
High Reliability Organisations continue to operate with performance almost free from errors and harm despite using complex technologies in extremely hazardous environments where minor failures can be catastrophic. They operate to avoid catastrophic failures, but if these failures eventually occur, they are setup to contain the consequences [6]. Various studies [1; 6; 7] have reviewed the five characteristics of these organisations, which were outlined by ref. [8]. The same authors [8] identified these as five key ideas of mindful infrastructure and attributed the performance of highly reliable organisations to them. The first three are preoccupancy with failure, reluctance to simplify, and sensitivity to operations, which define the organisation's capacity to deal with unexpected failures [6; 8]. The last two, identified as commitment to resilience and reference to expertise, deal with the capacity to contain the failures [6; 8]. These principles will be reviewed in detail in this section.  
**Preoccupancy with failure** is a characteristic that allows HROs to proactively identify signs of possible failures. Minor errors and near missies are treated as opportunities to learn and improve potential weaknesses [6; 8]. As an illustrative practice, \"pre-operatively people spend time identifying activities they do not want to go wrong. In handoffs or reports to oncoming staff, people discuss what to look out for\" [9]. As an example, the failure to report haze noticed in the horizon was identified as lack of preoccupancy with failure and one of the reasons for the Titanic disaster [6].  
**Reluctancy to simplify** \"shows how organisations continuously balance simplification and standardization of processes, with undue generalisations. They have standardized processes, yet actively seek divergent viewpoints that question received wisdom, uncover blind spots and detect changing demands\" [6]. Reference [6] provides the NASA Challenger disaster as an example of when management oversimplified the concerns on design flaws, which resulted in a disaster.  
**Sensitivity to operations** can be identified as \"fostering strong working relationships throughout the organisation, so that minor issues with operational processes or practices can be identified and fixed quickly before they worsen\" [1]. The HROs are alert to the operation details with the right people, competence, and motivation. Ref. [9] provided illustrative practice for sensitivity to operations as \"People interact often enough to build  
Figure 1: Proposed hybrid framework.  
a clear picture of what is happening here and now. People have a good'map' of each other's talents and skills. People have access to a variety of resources whenever unexpected surprises crop up\".  
**Commitment to resilience** is characterised by \"developing capabilities to cope with, contain, and bounce back from mishaps that have already occurred, before they worsen and cause more serious harm\" [9]. The lack of emergency response processes to enable emergency rescue missions was identified as lack of commitment to resilience [6].  
**Deference to expertise** describes the condition where decision making is yielded to a subject matter expert, regardless of their roles during emergencies. This is unlike what happens during normal operations, where there is reliance on a hierarchy with clearly defined roles and responsibilities [6]. The Piper Alpha incident was referred to as a clear example of failure to defer to expertise [6], where experienced staff qualified to make decisions during the emergency waited to receive shutdown instructions from their leadership.