Event Tree Analysis - ETA
An event tree is a visual representation of all the events
which can occur in a system. As the number of events increases,
the picture fans out like the branches of a tree.
Event trees can be used to analyze systems in which all
components are continuously operating, or for systems in
which some or all of the components are in standby mode
those that involve sequential operational logic and
switching. The starting point (referred to as the initiating
event) disrupts normal system operation. The event tree
displays the sequences of events involving success and/or
failure of the system components.
In the case of standby systems and in particular, safety
and mission-oriented systems, the event tree is used to
identify the various possible outcomes of the system following
a given initiating event which is generally an unsatisfactory
operating event or situation. In the case of continuously
operated systems, these events can occur (i.e., components
can fail) in any arbitrary order. In the event tree analysis,
the components can be considered in any order since they
do not operate chronologically with respect to each other.
more information: http://www.event-tree.com/