Anomaly Triggers

The Anomaly Triggers panel shows anomaly triggers assigned to the current asset. It may also show a preview chart, showing which triggers apply at which KPs or depths.

This panel only shows asset-specific anomaly triggers — it does not show triggers which may apply to event fields independent of asset. For example, if your Anode event is set to always raise a finding when its Depletion is greater than 75%, that would not be shown in this panel.

Anomaly triggers are pre-defined upper and lower bounds which are applied to event information. When the bounds are exceeded, IC-Inspection automatically creates a Finding on the event.

The Is Active column indicates with Yes or No whether the anomaly trigger is currently triggered. This is determined by the current incoming survey KP and Date/Time values:

• The survey KP value will be compared against the Start KP and End KP of the anomaly trigger.
• The survey Date/Time will be compared against the Date From and Date To of the anomaly trigger.
• The anomaly trigger must also be enabled.

When an anomaly trigger is violated, a yellow exclamation mark () will appear next to the field. You can set lower/upper bounds to be constant values (so a field might trigger if it was outside, say, 1 to 9) or to pull from a field, on this form or on another form. So for example if this field is Measured Wall Thickness, it might trigger if its value is less than Minimum Allowable Wall Thickness.

For Lookup List fields, the comparison is done of the lookup list item’s Value, not its Comment. So 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 trigger should be fired.

For Yes/No fields you can set the trigger to fire on any combination of Yes, No or blank; but you can’t compare to another field.

The Include Boundary tickbox controls whether exact matches cause the trigger to fire: if you have set a trigger to “Fail when inside Upper/Lower bounds”, your lower bound is 1 and your upper bound is 9, this is the difference between “1 < x < 9” and “1 <= x <= 9”.

You can optionally give an anomaly trigger a date range. If you set just a Date From, the trigger will apply only to event data from that date forward. If you set just a Date To, the trigger will apply only to event data from 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.

Caution

In most cases, Findings are generated at the time events are added or imported. There are however some scenarios in which the Anomaly Triggers utility should be run manually. These are 1) whenever anomaly triggers are edited; 2) when anomaly triggers exist on a calculation field; 3) before any Finding review sessions; or 4) after a bulk import of event data (particularly when anomaly triggers rely on events other than itself).

Triggers for a field independent of asset are found in NEXUS IC in Asset Information and Event Types. Anomaly triggers for specific assets can be configured in NEXUS IC by right-clicking on an asset and choosing Anomaly Triggers…. If you have both an asset-specific and a generic anomaly trigger on the same field, for assets with the asset-specific trigger, only the asset-specific trigger will apply. For assets with only a generic trigger, only the generic trigger will apply. Note that asset-specific anomaly triggers are specific to their asset — they do not automatically apply to an asset’s children.

A trigger can have an anomaly Code and a Severity, and you can have several different triggers on a single field, with different codes and/or severities. The dialog may also show a preview chart, showing which triggers apply at which KPs or depths.