fault tree analysis (fta) as a probabilistic risk assessment (pra) method is used to identify basic causes leading to an undesired event, to represent logical relation of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event. to conduct a quantitative fta, one needs a fault tree along with failure data of the basic events (bes). someti...

Fault Tree Analysis (FTA) as a Probabilistic Risk Assessment (PRA) method is used to identify basic causes leading to an undesired event, to represent logical relation of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event. To conduct a quantitative FTA, one needs a fault tree along with failure data of the Basic Events (BEs). Someti...

This paper considers a technique for calculating the unconditional failure intensity of any given non-coherent fault tree. Conventional Fault Tree Analysis (FTA) techniques involve the evaluation of lengthy series expansions and approximations are unavoidable even for moderate sized fault trees. The Binary Decision Diagram (BDD) technique overcomes some of the shortfalls of conventional FTA tec...

When the failure probability of a system is extremely small or necessary statistical data from the system is scarce, it is very difficult or impossible to evaluate its reliability and safety with conventional fault tree analysis (FTA) techniques. New techniques are needed to predict and diagnose such a system’s failures and evaluate its reliability and safety. In this paper, we first provide a ...

Development of a Computer-Aided Fault Tree Synthesis Methodology for Quantitative Risk Analysis in the Chemical Process Industry. (December 2004) Yanjun Wang, B.En., Zhejiang University, Hangzhou, China Chair of Advisory Committee: Dr. M. Sam Mannan There has been growing public concern regarding the threat to people and environment from industrial activities, thus more rigorous regulations. Th...

the traditional event tree analysis uses a single probability to represent each top event. however, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. the fuzzy set theory is universally applied to deal with this kind of phenomena. the main purpose of this study is to construct an easy metho...

this study focused on the public transport risk assessment in district one of ​​tehran through fault tree analysis involving the three criteria of human, vehicle and road in haddon matrix. in fact, it examined the factors contributing to the occurrence of road accidents at several urban black spots within district 1. relying on road safety checklists and survey of experts, this study made an ef...

Fault Tree Analysis (FTA) has become a popular tool for use in the Space Industry for the System Safety Engineer. The fault tree is used for everything from tracking hazard reports to investigating accidents, as well as presentations to management. Yet, experience in the space industry has shown the fault tree is used most often for purposes other than its original intent, namely for evaluating...

Safety is an important requirement for many modern systems. To ensure safety of complex critical systems, well-known safety analysis methods have been formalized. This holds in particular for automation sytsems and transportation systems. In this paper we present the formalization of one of the most wide spread safety analysis methods: fault tree analysis (FTA). Formal FTA allows to rigorously ...

This paper presents a method to include safety system conflicts into a fault tree analysis (FTA) with semantic extensions of fault events. The verification of the incoherent fault tree is done with an SMT-Solver. As an example a networked setup of medical devices for extracorporeal lung assist was analyzed. The method is developed as a basis for improved safety analysis of networked systems.