Executing an alarm management strategy is no small task. One of the hardest parts is sustaining the work effort. As plants change and expand, personnel turnover, and operations continue, nuisance alarms seem to creep back. For you to succeed in advancing your strategy, while keeping the peace, you must meet many challenges motivating personnel and juggling the integration of changes.
Long, long ago alarm tales
You knew you had an alarm management problem for quite some time: all of the signs were present. Operations managers recommended using both sides of line printer paper as a cost-cutting measure because of the high number of alarms and events. You noticed a rise in the failure rates of operator keyboards and trackballs. During plant startups and shutdowns, operators repeatedly hit the acknowledge key until the annoying alarm tone ceased; the alarm list was ignored. While this isnt true in all plants, its probably true in most. Your to do list includes looking into nuisance alarms but there was always some other project, more visible, with a potential for more financially tangible results.
Finally, you have the go a head to do something about this problem. Because of years of increased focus on plant safety, alarms are the best indicator of plant safety at your facility. Alarm management has visibility. Regulatory agencies are watching. This, like many other trends, varies by region in degree to which regulatory agencies enforce such programs. For example, in the U.K., the Health and Safety Executive (HSE) has threatened to shut down facilities without an alarm management program. In the U.S., bodies such as the Occupational Safety & Health Administration (OSHA) arent yet as aggressive but are catching up fast. Another reason for their focus is: more than 42% of reported incidents involve human error (Figure 1). Incidents included poor communication of alarm conditions, poor operator training (to deal with abnormal situations), and bypassed safety measures. Regulatory interest recognizes a simple truth: your operators are over-burdened with alarms.
Compare analysis results
To execute your project, you probably read various articles in trade magazines and other sources, which gave you advice such as measure, analyze, and improve or benchmark, plan, and implement. While this made perfect sense, the details arent clear. So, you started by trying to assess how bad the problem actually was to establish the baseline.
You tried to do some reporting through the control system; it was time-intensive and easy to miss something. So, you purchased a third-party alarm analysis software tool that collected the historical alarm and event data from the control system and the plant. Though there was some tuning of how the analysis software treated the alarms, this was definitely less painful than manually moving, sorting and writing queries against the data. You compared your analysis results with the Engineering Equipment and Materials Users Association (EEMUA) 191 guidelines, and your hand automatically slapped your forehead and slowly dropped down to your chin (Figure 2). This is a normal reaction when you find out the numbers are outrageously higher than the guidelines state. The data collected clearly showed, at least in some plant states, the operators at your facility were operating in a reactive mode instead of predictive (Figure 3). Reactive is where operators have to react to certain conditions due to being flooded with alarms instead of using them to avert potential problems before they happen, which is predictive.
After analysis of the data, you developed a multi-faceted approach that converted your overloaded or reactive alarm-annunciation status to more predictive. You followed one simple rule: if an operator isnt supposed to do something immediately, in response to an alarm, if that alarm isnt directly related to a root cause, its a nuisance alarm. From this you developed your goals:
- Low-hanging fruit: Reduce the number of nuisance alarms using analysis reports. The analysis tools pointed out some easy changes to consider that have little impact on operations.
- Alarm rationalization and documentation: The size of this effort depends on the scope and the size of the facility. The outcome of this goal is an alarm philosophy document that should act as the bible on the future handling of alarms at your facility. How this bible is used is important avoid imposing bureaucracy and overhead. Experience shows the best team to deal with these alarms is the team already in place.
- Dynamic alarm handling: Spikes of alarms occur during certain phases of production such as startups and shutdowns. Some of these alarms are routine and not relevant to safe operation. Reaching the desired EEMUA alarm statistics may require allowing operators to mask some alarms during busy times.
Hurrah! The job is over
The quick hits to get rid of those nuisance alarm pests happened rapidly and the operators seemed to appreciate the results. The alarm rationalization project was more involved. Thanks to help from a vendor your bible is progressing.
This took longer than expected, but is well worth it, as now that you feel youre in control of your alarm configuration. Also, the task you thought would be more difficult, dynamic alarm handling, was actually easier than expected due to new features in your latest control system that allow alarms to be dynamically hidden to the operator based on process conditions.
Although your results arent to the EEMUA recommendations, you can boast a 50% reduction during normal operations and close to 80% reduction in nuisance alarms during plant state transitions.
Months later, you decide to rerun some of the reports that you first ran for your benchmarking exercise, and its lucky you did. Your once impressive numbers no longer exist. How could this happen? ABB Engineering Services metrics indicate 97% of all new nuisance alarms come from one of three sources: