An event-tree analysis (ETA) visually resembles a fault-tree analysis but is fundamentally different from an FTA. An ETA is an inductive analysis which compared with the FTA (deductive) is performed in reverse order. Hence the effects of events under investigation are determined instead of their causes.
The objective of this analysis is to investigate faults and incidents in technical systems. Within the scope of this objective the potential consequences of a fault are determined. Starting with an initial event a tree structure is built which ultimately ends in the consequences which may potentially result from this event.
An event-tree analysis may be performed either qualitatively or quantitatively. In case of a qualitative analysis the effects of an occurring fault may be determined, for example. When a quantitative analysis is performed, the results are extended by the probabilities of the effects resulting from the fault under investigation.
This analysis methodology is plotted using graphic symbols. During the course of the analysis these symbols lead to a tree structure which exhibits the resulting signal paths or effect paths. Through structured plotting of these effect paths a complete modelling of the system can be achieved.