Fault Tree

This paper presents a Fault Tree (FT) based approach for quantitative risk analysis in the construction industry that can take into account both types of uncertainties including objective and subjective uncertainty. In this research, the identified basic events are first categorized based on the availability of historical data into probabilistic and possibilistic. The probabilistic and possibilistic events are represented by probability distributions and fuzzy numbers, respectively. The hybrid uncertainty analysis is then performed through combination of Monte Carlo simulation and fuzzy set theory. The probability of occurrence of top event is finally calculated using the proposed fault tree based hybrid uncertainty analysis method. The efficiency

In construction industry, several researches have been conducted in the area of QRA using

The proposed approach accounts for both types of uncertainties (i.e., probabilistic and possibilistic) as well as the interdependencies that exist among different events. The flowchart diagram of different stages of quantitative FTA using the proposed hybrid uncertainty analysis method is depicted in Fig. 1. As shown in this figure, in the first step the objectives of analysis using FT are identified. The top event is identified and the scope of FTA is defined in the second and third steps. In the fourth step, the root causes of top event are investigated and the basic events leading to the occurrence of top event are recognized. Then, the identified basic events are categorized based on the availability of historical data into probabilistic and possibilistic. The probabilistic and possibilistic events are represented by objective and subjective probability, respectively. Then, the fault scenarios leading to the occurrence of top event are identified by constructing the FT structure. The hybrid uncertainty analysis is performed through combination of Monte Carlo simulation and fuzzy set theory which is explained in detail in section 3 of this paper. The probability of occurrence of top event is now calculated using the proposed fault tree based hybrid uncertainty analysis method. Finally, by calculating the importance measure of each fault scenario, the response strategies can be adopted by manager for