Set Up Anomaly Triggers

You can set up anomaly triggers for fields in an Asset Information Group (AIG) or an event form. When an anomaly trigger is violated, a yellow exclamation mark (Anomalous) will appear next to the field.

Note

You can also set up asset-specific anomaly triggers. For more information, see Set Up Anomaly Triggers for Assets.

To set up a generic anomaly trigger for a field, proceed as follows:

  1. Start editing the required field in either of the following ways:

    • In case of an AIG field, choose Configuration ‣ Assets ‣ Information from the main menu, select the relevant AIG form in the top of the dialog and double-click the required field from the bottom of the dialog or select it and choose Edit.

    • In case of field in an event form, choose Configuration ‣ Events ‣ Event Types from the main menu, select the relevant event type in the top of the dialog and double-click the required field from the bottom of the dialog or select it and choose Edit.

  2. In the Edit Field Definition dialog (see Add/Edit Field Definition Dialog), go the the Anomaly Triggers tab.

  3. Choose Add to create a new anomaly trigger, or, if you want to change an existing anomaly trigger, select it and choose Edit.

  4. Enter data as follows:

    Field/Checkbox Name

    Description

    Type

    Describe the case when the anomaly should be triggered.

    Error Message

    If you want to set up an error message to be shown when the anomaly is triggered, you can define its text here.

    Enabled

    Tick this checkbox to activate the trigger. In this case, the value of the event field will be checked against this trigger. If this checkbox is not ticked, the trigger is ignored.

    Date From/Date To

    You can optionally specify a date range for an anomaly trigger. If you specify only Date From, the trigger will apply only to event data from that date forward. If you set only Date To, the trigger will apply only to event data till that date or earlier. If you set both, the trigger will apply only to event data within the specified range. In this way, you can change triggers to reflect new conditions, without causing spurious warnings on historical data. For example, if you decrease the operating pressure of an asset, this might decrease the minimum allowable wall thickness. Rather than editing the existing anomaly trigger, you can set a “To” date on that old trigger, and add a new trigger with a “From” date.

    Lower Bound

    Specify a constant value. If the field’s value is below this constant value, the anomaly will be triggered.

    Lower Bound (Field)

    Specify a field whose value should be compared to the value of this field. If the current field’s value is below the value of the field that you specify here, the anomaly will be triggered. For example, if this field is Measured Wall Thickness, the system might trigger an anomaly if its value is less than the value of the Minimum Allowable Wall Thickness.

    Upper Bound

    Specify a constant value. If the field’s value is above this constant value, the anomaly will be triggered.

    Upper Bound (Field)

    Specify a field whose value should be compared to the value of this field. If the current field’s value is above the value of the field that you specify here, the anomaly will be triggered. For example, if this field is Measured Wall Thickness, the system might trigger an anomaly if its value is more than the value of the Maximum Allowable Wall Thickness.

    Include Boundary

    Controls whether exact matches cause the anomaly to be triggered. For example, if you have set a trigger to “Fail when inside Upper/Lower bounds”, your lower bound is 1 and your upper bound is 9, your selection in this field determines whether the anomaly is triggered if the value is “1 < x < 9” or if it is “1 <= x <= 9”. If you select Yes, the anomaly is triggered also if the value of the field is equal to the upper or lower bounds.

    Code

    Specifies the code that indicates the type of the anomaly (see Code).

    Severity

    You can set several triggers on a single field, with a variety of different codes and/or severities (see Severity). If that anomaly trigger is violated on an event field, a finding of that code and severity will automatically be created. Severities let you equate dissimilar problems, for example, you can decide that a problem in one field is of the same severity as a problem in a different field.

  5. Click OK to save your changes.

Note

  • For Lookup List fields, the comparison is performed based on the lookup list item’s value, not its comment. For example, if you have a lookup list titled Anode Depletion, and its first entry has value “25” and comment “0 to 25% depleted”, NEXUS will use the “25” for purposes of determining whether an anomaly should be triggered.

  • For Yes/No fields, you can set the anomaly to be triggered on any combination of Yes, No or blank, however, you can’t compare it to another field.

  • If you delete an anomaly trigger, findings created from it won’t be deleted. If you want to delete all findings created from an anomaly trigger, don’t delete the anomaly trigger. Instead, modify it so that no data will be marked as anomalous (for example, you can set it to only flag data between -2 and -1 on a field with no negative values), then run the anomaly triggers functionality. Then, as a second step, you can delete the anomaly trigger.

See also