How exactly one can find out the influence of each risk component in Fault Tree Model?
Is that possible at all with model?
Fault tree analysis (FTA) is a top-down, deductive failure analysis in which an undesired state of a system is analyzed using Boolean logic to combine a series of lower-level events. This analysis method is mainly used in the fields of safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk or to determine (or get a feeling for) event rates of a safety accident or a particular system level (functional) failure.
In other words, how many tiny pieces can break when it breaks then what else breaks as a result.
The influence of each risk can be determined by understanding the system-wide consequences of the failure - which is not readily apparent in the FTA.
For example: An indicator light that fails to turn on could either fail to inform you the oil is overheating or that the trunk is not closed properly. The potential consequences are very different depending on the weather and the value of the baggage.
A full understanding of the system in question would be needed to understand and assess the influence of each risk. (And as I've often said, a PjM who doesn't understand the technicalities of their project is a ticking time bomb.)