Backlog = Scheduled Labor Hours / (Number of employees * Working Hours in a week)
The backlog shows how many hours of work that there are not enough employees to work on it. This may be common, however this is a number that should be looked at regularly to see if trends develop. A standard backlog of one week may not be a problem for your organization, but if you notice that it was a one day backlog last time you checked then the backlog may continue to grow to an unacceptable level.