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Results  - Event Tree

Let's look at the results from the event tree analysis of the 415V diesel-backed bus.

There are three sequences leading to the unwanted event "No power on the 415V bus" in the event tree. The consequence is given the ID: "NO POWER".

The results of the consequence analysis in the event tree show that the system, on an average year, is likely to fail 0,065 times due to failure of the external grid. The difference in result compared to that of the fault tree analysis depends on that the event: "Inadvertent isolation of the external grid" (basic event ID: ISO-D) is not included in the event tree model. It has no meaning there.

In this simple example a sequence analysis is not very useful, as the result merely is the same as each CutSet in the consequence analysis.

Consequence analysis:

The frequency for the consequence "NO POWER" is F=0,065 and the MCS-list for the analysis is presented in the table below



In the consequence analysis, the frequency for "NO POWER" is calculated with the condition that the external grid has failed (the initiating event). Therefore that event is present in all the MCS.

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