Since 1994, PAS has benchmarked hundreds of alarm systems in various industrial markets around the world. From our project databases, this paper presents examples of the worst, most overloaded alarm systems encountered. In addition, the possible solutions to these problems are discussed.
Alarm Management is the current "hot topic" in the process industries. Overloaded and poorly performing DCS alarm systems are common and have been identified as contributing factors in several major accidents including those at BP Texas City in 2005 and Texaco Pembroke refinery in the UK in 1994.
To improve an alarm system, it is essential to perform an initial benchmark. Benchmarking a system has many benefits. It provides a basis to compare a system against industry best practices as well as a reference point to measure improvements at the end of an alarm management project. Other benefits include creating solid data driven analysis to communicate the state of the alarm system to appropriate stakeholders at a site, and justify further investment in alarm system improvement. Finally, a significant benefit in a benchmark study is the identification of bad acting alarms. As a standard practice, PAS identifies bad acting alarms in the initial benchmark report. Our experience indicates that breakthrough gains can be realized simply by resolving the bad acting alarms.
There are several different alarm problems to examine, with differing solutions. In performing these analyses, some amazing phenomena have been documented, presented here as examples of how bad things can get.