Backlog tickets is a term used to refer to the unresolved tickets in a particular time period. There can be a number of reasons for said unresolved tickets - agent performance, ticket volume and dependencies.
Backlog tickets are a great metric to keep an eye on because they can help you figure out how efficient your support process is. They can also help you gauge a customer’s happiness level; if they have a lot of backlog tickets, they’re bound to be unhappy. You can mitigate this by assigning them an account manager who’ll make sure that all their tickets are taken care of properly.
If the number of tickets resolved every day is more or less the same over a time period but the number of backlog tickets increases continuously, then it’s a clear sign that you need to hire a new support agent.