Tom Nolan, ProSys
As I mentioned in Part 1, ISA 18.2 is more than just a standard, it’s become the industry accepted best practice.
Achieving compliance is not going to be possible without dynamic alarm management. As mentioned, alarms need to inform of abnormal situations. What is normal changes with the process state. When a plant is running, the bottom of a distillation tower being too cold is abnormal with undesirable consequences and action needs to be taken to mitigate those consequences. When the plant is down for maintenance, it is normal for the bottom to be cold, there are not undesirable consequences, and there is not action for anyone to take. It is doing what it is supposed to. If the low temperature alarm is relevant in the running state but not for the shutdown state, it can cause confusion and take up real estate that could show the operator where something abnormal for the shutdown state is occurring. If you do a good job of alarming what should be alarmed in the running state, you have almost certainly created a poor alarm system for the shutdown state.
Optimizing the alarms for the run state makes sense in term of time, but not risk.
- Processes hopefully spend the majority of the time in the running state.
- We know that 70% of incidents occur starting up or shutting down.
- Everyone operating the plant has the least amount of experience with these states.
- A non-dynamically managed alarm system can be more of a hindrance than a help in these situations.
Also in a shutdown, a lot of people are outside running around who are not as familiar with the facility as the folks who work there every day. There are more folks in the process area, and they are less able to keep themselves safe. The right alarms need to be coming in and not diluting with the ones that don't need to be coming in.
Proper alarm management is about the right alarms, not just less alarms. Do not just think in terms of reducing alarms. Instead, think in terms of having the right alarms, which is probably less than what you have now. Because you are alarming more things than you need to does not mean you are alarming everything you need to. Quite the contrary. If the alarm system was not well thought-out, you may very well be missing things you are liable to have in there. In a good rationalization, some alarms are probably going to be added. A review of the PHA and other process documentation needs to be done to insure what needs to be alarmed is being alarmed. ProSys is very experienced at doing this type of data mining and can provide assistance. This will make sure that you have the protections that you have identified that you need which will reduce the probability of having an incident.
In the event of an incident, you do not want to be in the position of having documented that you know you have the hazard, and that the protection you had in place was an alarm only to find out that the alarm was not really there. This happens much more than you would think! Everybody thinks it is there, but it is not. ProSys can help to reduce risk here. Use the lifecycle model in ISA 18.2 to achieve and stay in compliance and monitor performance with tools like Event KPI.
Bottom line is that compliance with ISA 18.2 is something that needs to be done and is a great investment on its own merits of safety and performance. Get help from the experts at Prosys with the tools and the know-how to successfully achieve and maintain compliance with ISA 18.2 and reap the benefits as well.