Event Tree Analysis (ETA)

Download the latest version of RAM Commander V8.5 (February 2015)


Event Tree Analysis is one of the most widely used methods in system risk analysis. It is an inductive failure analysis performed to determine the consequences of a single failure for the overall system risk or reliability. Event Tree Analysis uses similar logic and mathematics as Fault Tree Analysis, but the approach is different - FTA uses a deductive approach (from a system failure to its causes), while ETA uses an inductive approach (from a basic failure to its consequences).

An event tree itself is a visual representation of single failure sequences, together with a single failure impact on other events and on the whole system.

Event Tree Analysis Example
Main window of the RAM Commander's Event Tree Analysis Module

ETA Module Features
•  User-friendly and convenient tree building interface (zoom, export to clipboard as metafile, print, etc.)
•  Customizable graphical representation (colors of diagram elements, their styles, etc.)
•  Events Library
•  Event Probability assessment models:
   o user-defined
   o calculated (repairable/unrepairable/constant mission time/periodical tests)
   o linked to product tree element
   o linked to FMECA Failure Mode, NHE or End Effect
   o linked to Fault Tree basic event
   o linked to Fault Tree gate or tree top event
•  Different Event logic types:
   o Binary logic 
            - True/False 
            - Success/Failure
   o Multiple alternatives (for events where not only True/False or Success/Failure outcomes are considered)
•  Different Event probability types
   o Equal event probabilities in all sequences
   o Different event probabilities in different sequences (conditional probabilities)
See also:

RAM Commander homepage
Fault Tree Analysis Software Module
ALD Reliability and Safety Software Overview
Reliability&Safety Software Download
See ALD Reliability, Safety and Quality Services if you wish us to perform reliability prediction, analysis or other services for you.