Prioritization of critical risk influencing factors in quantitative risk analyses for offshore petroleum installations

Comprehensive and detailed investigations of various major offshore accidents have shown that multifarious risk influencing factors including technical, human, and organizational factors have a significant impact on the nonlinear accident sequences. Parallel efforts are being made to develop quantitative risk analysis models involving risk influencing factors. It is recognized that in order to keep quantitative risk analyses in a manageable size, it is essential to restrict the number of risk influencing factors for each failure event. This article describes an effort to prioritize critical risk influencing factors for offshore maintenance work. A prioritization index integrating the weight and the status of each risk influencing factor is developed to determine the most appropriate prioritization. A hierarchy tree is developed to structure the identified risk influencing factors. The unified fuzzy scoring criterion is established for evaluating the risk influencing factors status. The fuzzy analytic hierarchy process approach stressing the consistency of the fuzzy pairwise comparison is applied to evaluate the priority of each risk influencing factor. A sensitivity study is conducted to investigate the criticality of risk influencing factors. The case study demonstrates that the proposed method can be a practical tool for prioritizing critical risk influencing factors effectively for all failure events in the quantitative risk analysis model. The method can also be useful in handling uncertainties arising in quantitative risk analyses.