Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test, measuring,
and diagnostic equipment used in precision measurement. Consists of comparisons of two instruments, one of
which is a certified standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the
instrument being compared.
Remove/Install. To remove and install the same item when required to perform service or other maintenance
functions. Install may be the act of replacing, seating, or fixing into position a spare, repair part, or module
(component or assembly) in a manner to allow the proper functioning of a piece of equipment or system.
Replace. To remove an unserviceable item and install a serviceable counterpart in its place. Replace is
authorized by the MAC and shown as the 3rd position code of the SMR code.
Repair. The application of maintenance services1, Including fault location/troubleshooting2, remove/installation,
and disassembly/assembly procedures3, and maintenance actions4 to identify trouble and restore serviceability to
an end item by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module
(component or assembly), end item, or system.
Overhaul. That maintenance effort (service or action) prescribed to restore an item to completely serviceable/
operational condition as required by maintenance standards in appropriate technical publications (i.e., DMWR).
Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally
return an item to like-new condition.
Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like-
new condition in accordance with original manufacturing standards. Rebuild is the highest degree of material
maintenance applied to Army equipment. The rebuild operation includes the act of returning to zero those age
measurements (hours/miles, etc.) considered in classifying Army equipment/components.
Services- Inspect, test, service, adjust, aline, calibrate, and/or replace.
Fault locate/troubleshooting- the process of investigating and detecting the cause of equipment malfunctioning;
the act of isolating a fault within a system or unit under test (UUT).
Disassemble/assemble- encompasses the step-by-step taking apart (or breakdown) of a spare/functional group
coded item to the level of its least componency identified as maintenance significant (i.e., assigned an SMR code)
for category maintenance under consideration.
Actions- welding, grinding, riveting, straightening, facing, re-machining, and/or resurfacing.