Fault tree analysis enabling event

The event tree analysis is similar to the fault tree analysis and enables management to prevent loss producing events as a result of risks within the system. The event tree analysis is a predictive method of analyzing risks. 

The fault tree represents the result of the qualitative part of the analysis. This is based on questions such as How can this happen . These questions enable one to firstly relate the undesired event (also called TOP event) with the failure of subsystem functions such as cooling or energy supply. Successively these failures are broken down into the failures of sub-subsystems etc. until the level of the primary events is reached. Hence only portions of the plant of a size which can be handled by the human intellect at any one time are analyzed. These portions are then logically connected with analyses of other parts of the plant in order to eventually provide a model of the entire plant. 

The investigation has shown how the safety of the system can be improved. At the same time its availability is increased, although this was not the express objective of the analysis. Some of the results were already obtained in the qualitative part of the analysis. The quantification of the fault trees brought further insights and enabled one to identify areas of unbalanced safety measures. The latter are characterized by largely differing contributions of an individual initiating event to the expected frequency of an explosion (vid. Table 9.48). The proposals for... 

FTA is a tool employed in the analysis of complex systems to estimate the likelihood of a hazardous event. It has been applied, for example, in safety evaluations of nuclear power plants, space missions, air, rail, highway, marine and pipeline transport, liquefied natur gas, chemical manufacturing, and other hazardous material facilities. With this method, all material, personnel, and environmental factors of a complex system can be systematically presented. A well-constructed fault tree enables us to discover failure combinations that would not normally be discovered and provides for both qualitative and quantitative evaluation. 

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