Well, let's see who's awake and interested this morning...
Here's an interesting question that surfaced on the SCADA listserv this weekend.
Is alarm management for DCS (as most recently codified in the new EEMUA guidelines) the same as alarm management for SCADA systems? Are the criteria for number and type of alarms per unit time the same?
Aslan Muhamad Sufian, from TNB Transmission in Malaysia, says, "I think this guideline is more suitable for DCS. The EEMUA 191 states that the alarm arrival rate should be less than 1 alarm per 10 minutes. But IMHO, this condition may be ideal for a system that does not grow in I/O size over time, assuming alarm arrival rate is proportional to No. of I/Os."
Ron Southworth, however, thinks otherwise (and I happen to agree with him). "The [EEMUA 191] text does specify a context around DCS systems," Southworth wrote. "However, I would contend that alarm management requirements for our operators would be similar, if not the same, regardless of the system technology being based on DCS or SCADA architectures. The ability for humans to cognitively assimilate and act upon information does have limits regardless of the degree of expertise and training."
So, what's the real answer?
