Many people incorrectly interpret “dynamic alarming” as an easy fix for too many alarms. At face value, it’s a very attractive concept – Just put a big blanket on top of all that mess and the blanket will be smart enough to let the important stuff through.
That’s a really neat concept, but look under the hood and you’ll find that the time and labor required to successfully implement dynamic alarming are higher than you might have expected. You’ll also find that some of the engineering required is exactly the same as you thought you would avoid.
Dynamic alarming is a valuable technology to use. In fact, it is the only solution for many alarm management issues, such as suppressing alarms on equipment that is intentionally shutdown. Make sure you fully understand the role, the costs, and the benefits of dynamic alarming before interpreting it as a blanket solution for an alarm problem.
Many terms are used to promote the dynamic alarming concept: state-based alarming, advanced alarming, dynamic suppression, alarm subsumption. It all boils down to changing the alarms that confront the operator based on interpretations of plant state.
A dynamic alarm is typically triggered by alarm activity, which results in changes to alarm settings. Because dynamic alarming requires you to consider and design for multiple plant states for each alarm, the engineering involved is actually more intense than that required to design a system without a dynamic component.
In addition, an alarm system will not produce the exact alarm pattern for every abnormality. Designing, updating, and maintaining the trigger logic of a dynamic alarm system is similar to implementing advanced control in that it requires some kind of model. For a dynamic alarm system to be reliable and for it to successfully reduce risk, it is critical that not only are the alarm settings right but also that they are subjected to rigorous change management procedures. Changes to the alarm settings will not only affect what the operator sees, but they very well can disrupt or disable the dynamic logic.