A Fault Tree Analysis (FTA) is useful to organize thinking about how failures can arise – both single-fault conditions and multiple, simultaneous faults that can lead to hazardous situations.

Subsequent Assessments

The FTA can work hand-in-hand with subsequent assessments (e.g., FMEAs) to prevent divergence on causes and hazardous situations.

The top of the tree could be harm and lower nodes being how the harm can be realized.

Leaves in the Tree

The standard FTA process is then used to break down how each hazard can occur, ultimately resulting in the initiating events as “leaves” in the tree.

The use of ‘and’ and ‘or’ gates in the FTA can also support compliance with IEC 60601-1 where single faults and multiple simultaneous faults that can lead to hazardous situations must be cited for test lab assessment.