When backlog is concentrated in a few assignees, not the whole queue
A queue can look manageable from far away and fragile from close up.
That usually happens when backlog is not spread across the team in a healthy way. Instead of many people holding a reasonable amount of open work, a few assignees quietly end up carrying most of the load, most of the oldest tickets, or both.
The top-line backlog number does not tell you that. It simply tells you how many unresolved tickets exist.
That is why backlog concentration matters. The queue may not have a backlog problem in aggregate. It may have an ownership problem.
Why concentration changes the meaning of backlog
Imagine two teams with the same number of open tickets.
On one team, work is distributed evenly enough that follow-up stays predictable. On the other, two people hold a disproportionate share of the queue and also own the oldest tickets.
Those are not the same operating conditions.
Concentrated backlog tends to create:
- older unresolved tickets
- uneven customer wait time
- more escalations to overloaded owners
- more context switching
- more pressure to close work too quickly
The result is a queue that looks stable at the top level while service quality gets less consistent underneath.
Why this happens
When a few assignees end up holding most of the backlog, it is usually because the system drifted, not because a few people suddenly became worse at their jobs.
Routing stopped balancing well
Assignment rules may be sending too much of one ticket type to the same people.
Specialists became the default overflow point
Experts often attract more and more difficult work until the queue quietly depends on them for too much.
Ticket age is hiding behind ticket count
Some agents may have a normal number of open tickets, but the tickets they do hold are much older and harder to move.
Ownership after handoff is unclear
When tickets bounce or follow-up responsibility is fuzzy, backlog tends to settle around the people who are most willing to keep carrying it.
What to review instead of the blended backlog number
If the queue feels uneven even though total backlog looks manageable, review:
- Zendesk Backlog by Assignee Report
- Zendesk Backlog Aging Report
- Zendesk Tickets per Agent Report
- support metrics dashboard
Those views answer better operational questions:
- Who is holding the work?
- Who is holding the oldest work?
- Is the concentration persistent or temporary?
- Is the issue volume, complexity, or distribution?
The trap in using count alone
The most common mistake is to look only at open-ticket count by person.
That matters, but it is not enough.
An assignee with twenty fresh tickets may be in better shape than someone with eight tickets that are all weeks old, full of follow-up debt, or tied to hard-to-resolve issues. That is why ticket aging belongs in the same review as backlog concentration.
The real question is not just “Who has the most open tickets?”
It is “Where is unresolved work becoming risky?”
What good looks like
A healthy queue does not mean every agent has the exact same number of open tickets.
It means:
- workload distribution roughly matches role and specialization
- no one quietly becomes the default holding zone for old work
- aging and priority are visible alongside open-ticket count
- managers can explain the concentration when it exists
Some concentration is normal. Hidden concentration is the real problem.
How to respond when backlog sits with a few people
If the same assignees keep carrying most of the queue:
- Review whether assignment rules are still doing what you expect.
- Check whether specialists are taking on too much work that should stay upstream.
- Compare open count and aging together, not separately.
- Look for rising reassignment or follow-up complexity in the same queue.
- Decide whether the fix is routing, escalation design, staffing, or queue ownership.
The point is not to flatten every difference between assignees. It is to make sure concentration is deliberate, manageable, and visible.
The main takeaway
When backlog is concentrated in a few assignees, not the whole queue, the queue can look healthier than it really is.
The top-line backlog metric still matters, but it is too broad to tell you whether work is distributed in a way the team can actually sustain.
If customer wait time feels uneven, if old tickets keep resurfacing in the same places, or if a few people always seem to carry the hardest unresolved work, review backlog by owner. That is usually where the real queue story starts.