For industrials and defence contractors, backlog is the closest thing to visibility on future revenue. It is disclosed with an expected conversion schedule, which tells you how much is deliverable within twelve months.
Backlog can be cancelled, repriced or delayed, so quality matters as much as size. A backlog padded with options and letters of intent is worth far less than one of firm, funded contracts.
Example: Northwind Tools ends the year with $312M of backlog against $840M of revenue, up 18%. The company expects 71% to convert within twelve months.
Related: book-to-bill, remaining-performance-obligations, revenue, guidance, deferred-revenue