Patterns

The Event Processor detects regularities in the stream of events arriving from the monitored asset. These regularities are detected as a hierarchy of stable (persistently recurring) patterns, which can be either simple patterns (sequences of events) or composite patterns (sequences of patterns). The patterns that form a composite pattern are called subpatterns.

A sequence of events or patterns is considered recurrent if its constituent elements follow the same order, and the time intervals between similar elements in different sequences differ from each other by no more than a specific maximum range. The allowable range of intervals between the pattern elements is calculated considering the value of the Coefficient defining the permitted dispersion of the pattern duration parameter. Patterns are the result of the specific facility's adopted practices, prescribed procedures, or technical specifics of the industrial process.

The Event Processor presents the detected regularities as a layered hierarchy of nested elements (pattern structure) down to the event level. Events are the first layer elements, simple patterns are the second layer elements, and composite patterns are the third and higher layer elements. Event parameter values are elements of the null layer.

A pattern is registered once by the Event Processor service. When an event stream is received, the Event Processor recognizes previously detected patterns. If patterns are found that do not match previously detected regularities, the Event Processor registers new patterns.

New patterns also include the sequences of events or patterns with a deviation in the order or composition of subpatterns (for example, turning on an industrial unit before the operator has arrived at the workstation) or with significant changes in the intervals between events or subpatterns even though their sequence is preserved (for example, turning on an industrial unit immediately after or a lot later than the operator arrived at the workstation). Thus, the Event Processor registers patterns with a new structure.

New patterns may indicate an anomaly in the monitored asset operation. You can view the structure of the new pattern and examine its deviations from the structure of previously detected patterns.

If a newly identified sequence of events or patterns begins to repeat in a persistent manner, this sequence is converted to a stable pattern.