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Fault Tree Analysis Diagram

Fault Tree Minimal Cut Sets

Fault tree analysis is one of the most popular techniques used in safety analysis and risk analysis studies.

The first step of the fault tree analysis process is to produce the minimal cut set list for each system TOP event. The minimal cut set list effectively describe the combinations of component failures that cause the TOP event to occur.

Component failure and repair data is not required when evaluating the minimal cut set list of the system unless a probabilistic cut-off is being applied to eliminate highly improbable failure combinations. Cut-offs are applied to reduce the number of minimal cut set list to a manageable size when evaluating large fault trees.

The minimal cut set list for a fault tree may be obtained using Boolean algebra techniques. These techniques involve representing the gates in a fault tree with the equivalent Boolean expressions. The Boolean variables in an expression will represent the gates and basic events in a fault tree. Each gate and basic event in the fault tree should be given a unique name.

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