Fault tree analysis overview

All team members should be familiar with PrHA objectives, the PrHA method to be used, and their roles in performing the PrHA. A 1- or 2-hour overview at the beginning of the first team review session is generally sufficient for this purpose. However, the more demanding PrHA methods, such as fault tree analysis (FTA), require more training and/or a greater depth of experience than less-rigorous methods, such as what-if and checklist analyses. 

Identification and quantitative estimation of common-cause failures are general problems in fault tree analysis. Boolean approaches are generally better suited to mathematically handle common-cause failures. The basic assumption is that failures are completely independent events, but in reality dependencies will exist and these are categorized as common cause failures (CCFs). Both qualitative and quantitative techniques can be applied to identify and assess CCFs. An excellent overview of CCF is available (AIChE-CCPS, 2000). 

A Brief Overview of Selected System Safety Analytical Approaches Working with the Risk Assessment Matrix Preliminary Hazard Analysis Energy Flow/Barrier Analysis Failure Modes and Effects Analysis Fault Tree Analysis... 

R.B. Patil, L.Y. Waghmode, P.B. Chikali, T.S. Mulla, An overview of fault tree analysis (FTA) method for reliability analysis life cycle cost (LCC) management, lOSR Journal of Mechanical. Civil Engineering (lOSR-JMCE). 

FTA emphasizes the lower-level fault occurrences that directly or indirectly contribute to a major fault or undesired event. The technique is one of "reverse thinking" where the analyst begins with the final undesirable event that is to be avoided and identifies the immediate causes of that event [11]. By developing the lower-level failure mechanisms necessary to produce higher level occurrences, a total overview of the system is achieved. Once completed, the fault tree allows an engineer to fully evaluate a system safety or reliabihty by altering the various lower-level attributes of the tree. Through this type of analysis, a number of variables may be visualized in a cost-effective manner. 

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