Rule-based reduction of alarm signals in industrial control

The proper handling of alarms is crucial to any automated process control. In practice, many alarms are only distractive and do not represent a potentially dangerous situation. This paper presents a methodology and a computerized tool that aims to remove such nuisance alarms, a so-called alarm cleanup. This is a general, systematic approach that takes advantage of the control system's built-in functions, and is a first step to an improved overall alarm situation. By the strong reduction of the alarm count, the efficient construction of fault diagnosis and isolation models becomes feasible. In a typical case study, the number of alarms received at the remote control room of an operational bio-fueled District Heating Plant was effectively reduced by 83%.