Aiding Alarm Rationalization by Automatic Identification of various sequential patterns in large volume of Alarm and Event log data

Abstract

The main problem with modern Industrial Alarm System is that the operators receive far too many alarms than they can handle. Many of the alarms presented to the operators are nuisance in nature such as chattering alarms, redundant alarms, consequential alarms, and alarms with no action. Such alarms superfluously increase the alarm load to an operator, do not essentially indicate any real abnormal situation and more importantly do not require any corrective actions by the operator. Being overwhelmed by large number of nuisance alarms, operators always face tough challenge in identifying the real alarms which demands prompt operator actions and are often buried in the pool of nuisance alarms. It is therefore necessary to reduce the alarms loads of an operator by systematically identifying the nuisance alarms and presenting only the real useful alarms to the operators. Also, there are some alarms which require well defined operator actions to bring them back to normal. When these alarms get triggered operators are supposed to take a well-defined set of corrective action in order to normalize them. Identification of these alarms for which there is a consistent operator action would be of immense help since operators can immediately focus their attention on these alarms whenever they occur and carryout the necessary actions. The main goal of Alarm rationalization is to minimize alarm load to the operators by presenting only the alarms that are relevant and require operator actions. Alarm Rationalization process by and large is carried out manually. It is quite tedious, time consuming and requires a lot of manual efforts. To solve the these challenges and to aid in Alarm Rationalization process, a novel approach has been proposed in this paper for identifying the nuisance alarms by analyzing the large volume of Alarm and Event log data. Several Alarm Rationalization activities (such as: Changing Alarm Configuration settings, Alarm Suppression, Alarm grouping, Alarm removal, Alarm Prediction, Standardization of Alarm response Procedure) can be performed by based on the identified chattering alarms. The proposed approach is illustrated through some examples obtained by analysing the Alarm and Event log data from petrochemical and water treatment plants in Singapore.