The Event Tree Diagram pane displays the event tree selected in the Event Tree Table. The first column in the event tree represents the initiating event. In a continually operating system, this is generally the event that disrupts normal system operation. In a standby system, this is generally some unsatisfactory event or situation that presents itself.

Any additional columns inserted in the event tree represent the events that follow the initiating event. While event order can be arbitrary in a continuously operating system, it must be sequential in a standby system as operational logic and the switching of components is involved.

Each column and branch inserted in the event tree has its own set of properties. For more information, see:

You can link a column or branch to a fault tree gate or event, a FMEA tree item, or a system tree item. The column or branch then uses the calculation properties for the item to which it is linked. For more information, see Data Links.