An event tree is an inductive analytical diagram in which an event is analyzed using
Boolean logic
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denote ...
to examine a chronological series of subsequent events or consequences. For example, event tree analysis is a major component of nuclear reactor safety engineering.
[Wang, John '' et al.'' (2000). ]
An event tree displays sequence progression, sequence end states and sequence-specific dependencies across time.
Analytical tool
Event tree analysis Event tree analysis (ETA) is a forward, top-down, logical modeling technique for both success and failure that explores responses through a single initiating event and lays a path for assessing probabilities of the outcomes and overall system analy ...
is a logical evaluative process which works by tracing forward in time or forwards through a causal chain to model risk. It does not require the premise of a known hazard. An event tree is an inductive investigatory process.
In contrast, the
Fault tree analysis
Fault tree analysis (FTA) is a type of failure analysis in which an undesired state of a system is examined. This analysis method is mainly used in safety engineering and reliability engineering to understand how systems can fail, to identify t ...
(FTA) evaluates risk by tracing backwards in time or backwards through a cause chain. The analysis takes as a premise a given hazard. FTA is a deductive investigatory process.
Applications
An event tree may start from a specific initiator such as loss of critical supply, or component failure.
[Compare Northeast Blackout of 2003#Causes.]
Some industries use both fault trees and event trees. Software has been created for fault tree analysis and event tree analysis and is licensed for use at the world's nuclear power plants for
Probabilistic Safety Assessment
Probabilistic risk assessment (PRA) is a systematic and comprehensive methodology to evaluate risks associated with a complex engineered technological entity (such as an airliner or a nuclear power plant) or the effects of stressors on the environm ...
.
See also
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Event structure In mathematics and computer science, an event structure represents a set of events, some of which can only be performed after another (there is a ''dependency'' between the events) and some of which might not be performed together (there is a ''con ...
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Root cause analysis
In science
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earliest archeologic ...
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Ishikawa diagram
Ishikawa diagrams (also called fishbone diagrams, herringbone diagrams, cause-and-effect diagrams) are causal diagrams created by Kaoru Ishikawa that show the potential causes of a specific event.
Common uses of the Ishikawa diagram are product ...
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Why-Because analysis
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Failure mode and effects analysis
Failure mode and effects analysis (FMEA; often written with "failure modes" in plural) is the process of reviewing as many components, assemblies, and subsystems as possible to identify potential failure modes in a system and their causes and effe ...
(FMEA)
Notes
References
* National Research Council (US), Committee on Environmental Impacts Associated with Commercialization of Transgenic Plants, Board on Agriculture and Natural Resources, Division on Earth and Life Studies. (2002). ''Environmental Effects of Transgenic Plants: the Scope and Adequacy of Regulation.'' Washington, D.C.: National Academy Press.
OCLC 231950695* Wang, John X. and Marvin L. Roush. (2000). ''What Every Engineer Should Know About Risk Engineering and Management.'' London: CRC Press.
OCLC 5030452
Quality
Reliability engineering
Risk analysis methodologies
Safety engineering
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