Feeder documents, analytical trees

Analytical trees can be used in a variety of ways in the system safety effort. The most common application of analytical trees in current system safety programs is probably the use of fault trees for fault tree analysis (FTA). However, analytical trees can also be used as planning tools, project description documents, status charts, and feeder documents for several hazard analysis techniques (including fault tree analysis). Analytical trees can be multipurpose, life cycle documents and represent one of the most useful tools available to managers, engineers, and safety professionals. 

Analytical trees are also very useful as feeder documents for several hazard analysis techniques, for example, failure mode and effects analysis (Chapter 14), fault tree analysis (Chapter 15), energy trace and barrier analysis (Chapter 13), and project evaluation tree analysis (Chapter 16), the primary hazard analysis tools for many projects. Virtually any analytical technique or any type of analysis can be simplified by starting with the analytical tree as a base document. 

The scope is easily defined if an analytical tree is used as a feeder document (Chapter 10). The indenture levels can be identified by specifying the number of tiers of the tree to be included in the analysis (limits of resolution). A functional FMEA includes upper and/or middle tiers only a hardware FMEA includes the entire tree. 

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