The most common causes for an increase in EWT for a split priority level are:
The number of calls that are in queue increases.
Agents log out.
Agents go on break or are otherwise in the AUX work mode.
Agents are moved to another split.
Agents with multiple splits answer an increasing number of calls in other splits.
Following are the other conditions that can increase the EWT for a split priority level:
The average talk time increases.
The number of calls at a higher priority increases.
The number of direct agent calls increases.
The number of RONA calls increases.
The number of abandoned calls decreases.
The number of calls that are queued in this split but answered in another decreases.