## 6 Conclusions and Future Works  
The PGM mine LHD fire HP incident was investigated using the proposed hybrid model which integrated the reliability analysis techniques--FTA, RBD, FMECA, and AHP. The FTA identified the direct and contributing causes of the incident, the basic events, and how they relate to each other. The RBD extended the analysis from the FTA to identify weaknesses in the model. The analysis showed the need to seriously consider the contributing causes when analysing failures. It also showed the importance of basic event 2, 'poor routing of cables', as it controlled two backs on the RBD (1 and 3). Using the RBD analysis, the cut sets were identified, which showed how basic events 4 and 5 weakened the whole model. The FMECA identified the effects of the failure modes associated with the basic events on the direct causes and assigned the RPNs. The analysis showed that basic events 2, 4, and 5 had the highest priority numbers, suggesting priority in allocating resources should be given to these failure modes. Finally, the AHP showed that on the direct causes, basic event 2 was given the highest priority based on the criteria used, which consider the importance of safety of impact followed by probability of reoccurrence before the cost of devising a solution. Of the contributing causes, based on the AHP analysis  
Figure 7: A Summary of the hybrid framework and how it was applied to the chosen case study. using the HRO principles as alternatives, event 6 was given the highest priority based on the criteria used, which consider the importance to consider preoccupancy with failure followed by sensitivity to operations, reluctance to simplify before considering commitment to resilience, and deference to expertise, respectively. In general, the analysis showed the importance of event 2, 'poor routing of cables', to prevent failure by controlling the fuel and ignition sources. If the cables for the additional systems were correctly routed, the risk would have been significantly reduced. To prevent the TOP event after initiation, the importance of basic events 4 and 5, which were related to failure of the fire suppression system, was demonstrated. If the fire suppression system was able to extinguish the fire after initiation, then the risk of the TOP event would also have been significantly reduced. Based on the perspective of HRO principles, the importance of anticipation of the failure, particularly preoccupancy to failure in this incident, is demonstrated. Priority is given to poor risk management, which would significantly contribute to preventing the failure. The weakness of the model applied is its dependency on personal judgement, which can result in bias and inconsistencies. These can be eliminated by employing a group of experts to perform the analysis, especially when ranking is required. The model only applied the HRO principles on the pairwise comparison for the AHP analysis. To give a more detailed approach, we proposes the use of organisational reliability maturity models in future works. It is hoped that the proposed framework flowchart of the integrated methodology will be a further contribution to the existing ones on risk assessment, such as those in refs. [19; 20; 21], with the added benefits of including principles of HRO and multiple criteria decision making using AHP. The hybrid model provides extra information that is not captured using any single model on its own. The hybrid model can also be extended to incorporate human reliability analysis and Bayesian networks [22], software reliability [23], and in various other applications such as oil and gas pipelines [24], construction [25], buildings, and complex systems in general [26]. Conceptualization, T.G. ; Methodology, A.W.L. ; Validation, A.W.L. ; Formal analysis, T.G. ; Investigation, T.G. ; Writing--original draft, T.G. ; Writing--review & editing, A.W.L. ; Project administration, A.W.L. ; Funding acquisition, A.W.L. All authors have read and agreed to the published version of the manuscript.