Similarity Analysis of Industrial Alarm Flood Data

Flooding of alarms is a very crucial problem in process industries. An alarm flood makes an operator ineffective of taking necessary actions, and often risking an emergency shutdown or a major upset. In this work, the flooding of alarms is discussed based on the standards presented in ISA 18.2. A new analysis method is proposed to investigate similar alarm floods from the historic alarm data and group them on the basis of the patterns of alarm occurrences. A case study on real industrial alarm data is also presented to demonstrate the utility of the proposed analysis. Note to Practitioners-In an industrial plant, alarms are designed to inform the operator about any fault or abnormality in the operation. However, alarm systems are not always designed, implemented, and maintained properly. This usually results in an excessive number of enunciated alarms, most of which are false or nuisance. Specifically, during a plant upset, operators receive far more alarms that they can handle (hundreds or even thousands of alarms in a short period of time). This is known as an alarm flood or alarm shower. Our study shows that in some cases, alarm floods follow similar patterns. As a result by studying and classifying flood patterns, it is possible to find the root cause of an abnormality based on the history of the plant and previous similar floods. This allows the operator to react to a plant upset at the early stages of or even before an alarm flood.