This reports how many of the modules seen on this phase are actually delivering output normally, the healthiest of the module-count breakdowns and the figure that most directly determines whether this phase currently has adequate active capacity. It is the number an admin watches most closely for immediate operational risk; a drop in this count while tsiPhaseNbModConfigured stays the same means fewer modules are actively carrying load right now, regardless of whether the missing ones are off, failed, or unseen. An admin's primary phase-health alert would likely trigger directly off this count falling below whatever minimum the phase needs to safely carry its current load.