At maintenance facilities, such as might be found at Main Operating Bases, inventory is controlled by site personnel.
Maintenance personnel will formally "turn-in" unserviceable items for repair, receiving a funding credit in the process.
Maintenance personnel can also be issued repaired or new items back from inventory.
In the Navy/Marine Corps supply system repairable items are identified with certain two character cognizance symbols (COGs) and one character Material Control Codes (MCCs).
In the United States Air Force, repairables can be identified by their ERRC designation or SMR code.