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ReliaSoft's Failure Criticality Index (RS FCI) is a relative index showing the percentage of times that a failure of this component caused a system failure. For component [math]\displaystyle{ A }[/math] , this is 63.93%. This implies that 63.93% of the times that the system failed, it was due to the fact that component [math]\displaystyle{ A }[/math] failed.
[math]\displaystyle{ {{F}_{ZD}} }[/math] is a special counter of system failures not included in [math]\displaystyle{ Componen{{t}_{NSDF}} }[/math] . This counter is not explicitly shown in the results but is maintained by the software. The reason for this counter is the fact that zero duration failures are not counted in [math]\displaystyle{ Componen{{t}_{NSDF}} }[/math] since they really did not down the system. However, these zero duration failures need to be included when computing RS FCI.
It is important to note that for both RS DECI and RS FCI, and if overlapping events are present, the component that caused the system event gets credited with the system event. Subsequent component events that do not bring the system down (since the system is already down) do not get counted in this metric.
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