Also known as: WIP, unbilled work, work in process.
Where WIP hides
In reports that were emailed to the client but never registered as sent, in jobs technicians consider finished but nobody closed, and in variations that were done but never written down.
WIP in AMPS
In AMPS a job marked ready for invoicing is immediately visible to administrative staff, who can process invoices promptly, and reports are sent from AMPS so the send is recorded. The jobs page and Power BI show open jobs by status and age.