Backlog
A support backlog is the accumulation of unresolved tickets that have not yet been answered or closed.
A backlog forms when more tickets arrive than the team can resolve. It represents deferred work: every ticket in the backlog is a customer still waiting. Some backlog is normal, but a growing backlog signals that demand is outpacing capacity.
Teams track backlog size as a snapshot metric — "how many open tickets do we have right now?" — and alongside inflow vs. resolution rate to see whether the backlog is shrinking or growing. A consistently flat or growing backlog is an early warning sign.
Clearing a backlog typically requires either more capacity, faster resolution per ticket, or reducing inflow through better self-service. Short-term surges are often handled by temporarily shifting team priorities.