Dehumidifiers, air movers, heaters and pumps look alike and move constantly. A technician loads six machines for one job and brings four back from another, and the yard list is updated from memory at the end of the day.
When a customer asks how many units were delivered, or a machine has to be found, you need to know which serial number went out on which job and when. A handwritten delivery note rarely lists the serial numbers.
An asset tag on every machine and a barcode on every job ticket turn each loading and each return into a few seconds of scanning.