MADE 3.9.1 User Manual > Fault Tree

Fault Tree Analysis

Fault Tree Analysis (FTA) presents the sequence of events leading to an end-effect

(Top Event) selected.

FTA is a top-down approach which involves selecting a system failure (Top Event),

compared to a Failure Modes and Effects Analysis (FMEA) which is bottom-up approach

where failure paths are traced from their original cause through the system to the

nominated end-effect. FTA identifies all failure paths that can potentially lead to

the Top Event.

Assumptions & Limitations

The user needs to be aware of several assumptions when generating a FTA:

Select and enable the RAM module
Right-click an item of interest from the System Model editor or Project Explorer viewer Note: This item is treated as the 'end-effect' item regardless of where

the pre-defined end-effect item is currently set in the Project Explorer.

[Image: faulttreemenu.png]

The Fault Tree editor consists of 3 sections:

Top-Effects: Lists the failure mode responses of the end-effect item. If reliability data has been entered then the probability of occurrence for each response will also be displayed. Since only certain end-effect failure responses lead back to a limited number of functional failures, the user should select and compare top-effects and their corresponding fault trees. [Image: FaultTreeProbTopEvents.png]
Cut-sets: Lists each single cut-set that leads to a Top Event by the name of the Basic Event. This can be displayed in list or tree format. [Image: faulttreecutsets.png]
Fault Tree Diagram: will display fault trees of the Top Events selected in (1). [Image: faultTreeDiagram.png]