There are three possible relationships that a failure mode can have with the various output functions that are defined on the same object:
Always Affects - the effect of the failure mode is always visible as a degradation of the affected function
Sometimes Affects - the effect of the failure mode is sometimes visible as a degradation of the affected function
Never Affects - the failure mode has no effect upon the given function
Note: Although, "Always Affects" may at first appear to be the most basic setting,"Sometimes Affects" is actually the most diagnostically conservative relationship between failure modes and functions. For each failure mode,the specific output functions that are affected by that failure are specified in the tree that appears on the right side of the Failure Modes panel (depicted below).
In this tree (which lists all of the output functions defined for the object) the Analyst can specify whether a given failure mode "always" (blue checkmark), "sometimes" (blue checkmark with red question mark) or "never" (empty checkbox) visibly affects each function defined for the selected object. The settings in this tree will dictate the types of hybrid diagnostic inferences that can be performed by eXpress'shybrid diagnostic capability.
How to Define Affected Functions for a Failure Mode
Choose the Failure Modes tab within the context panels.
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Highlight the desired failure mode on the Failure Modes panel.
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In the Affected Functions tree on the right side of the Failure Modes panel, click repeatedly on the checkboxes listed beside each output function until the correct relationships (No Affect, "always affects", "sometimes affects", etc.) have been specified. OR
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Use Design Menu "Failure Mode" commands "Convert Affected Functions to" or "Convert All Affected Functions to"
Note: The Default Setting can be changed using the Design Menu "Failure Mode Options" command.
