Remove/Install. To remove and install the same item when required to perform service or other maintenance functions.
Install may be the act of emplacing, seating or fixing into position a spare, repair part or module (component or
assembly), in a manner to allow the proper function 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 is shown as the 3rd position code of the Source, Maintenance, and Recoverability (SMR) code.
Repair. The application of maintenance services, including fault location/troubleshooting, removal/installation, and
disassembly/assembly procedures, and maintenance actions to identify troubles, and restore serviceability to an item
by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module (component or assembly),
end item, or system.
The following definitions are applicable to the repair maintenance function:
Services - Inspect, test, service, adjust, align, calibrate, and/or replace.
Fault location/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).
Disassembly/assembly-The step by step breakdown (taking apart) of a
spare/functional group coded item to the level of its least component, that is
assigned an SMR code for the level of maintenance under consideration (i.e.
identified as maintenance significant).
Actions-Welding, grinding, riveting, straightening, facing, machining, and/or
Overhaul. That maintenance effort (service/action) prescribed to restore an item to a 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
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.
Explanation of Columns in the MAC.
Column 1. Group Number. Column 1 lists functional group code numbers, the purpose of which is to identify
maintenance significant components, assemblies, subassemblies, and modules with the next higher assembly. End
item group numbers are 00.