How many alarms can an operator handle?

The Center for Operator Performance (COP), a Dayton, Ohio, consortium that includes operating companies and automation vendors, has commissioned Louisiana State University (LSU) to conduct a series of studies over the past two years to answer the question of plants generally accepting the engineering equipment and materials users' association/International society for automation (EEMUA/ISA). The first study involved LSU engineering and construction management students and used five alarm rates on a pipeline simulator. Through this study, it was found that fewer alarms presented to an operator will result in quicker resolution of abnormal situations. The second study found that a professional operators faced fewer of the highest priority alarms at an alarm rate of 30 alarms in ten minutes than students saw at an alarm rate of ten alarms in ten minutes. This research raises two questions, first is that are the ISA and EEMUA targets correct and could an operator handle more alarms.