This PerfCounter64 counter reports a count of Severely Errored Seconds, tallied over the current interval. An admin uses it as a reliability metric distinct from raw error counts, since it reflects how many whole seconds were affected rather than how many individual errors occurred. 46 seconds logged in cmFlowStatsSES for flow 1 in one interval, concentrated in a short burst rather than spread evenly, points an operator toward a single transient event (like a brief optical glitch) rather than steadily degrading hardware.