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 onto position a spare, repair part or module
(component or assembly) in a manner to allow the proper functioning of an equipment or system.
Replace. To remove an unserviceable item and install a serviceable counterpart in its place. "Replace" is
authorized by the MAC and assigned maintenance level is shown as the third position code of the SMR code.
Repair. The application of maintenance services1 including fault location/troubleshooting2, removal/installation,
disassembly/assembly3 procedures, and maintenance actions4 to identify troubles and restore serviceability to an
item by correcting specific damage, faults, malfunction or failure in a part, subassembly, module (component or
assembly), end item or system.
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-new condition.
Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a likenew
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 (e.g., hours/miles) considered in classifying Army equipment/components.
B.3 EXPLANATION OF COLUMNS IN THE MAC, SECTION II.
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 to the next higher assembly.
Column 2, Component/Assembly. Column 2 contains the item names of components, assemblies,
subassemblies, and modules for which maintenance is authorized.
Column 3, Maintenance Function. Column 3 lists the functions to be performed on the item listed in column 2.
(For detailed explanation of these functions, see paragraph B.2.)
Column 4, Maintenance Level. Column 4 specifies each level of maintenance authorized to perform each
function listed in column 3 by indicating work time required (expressed as man-hours in whole hours or decimals)
in the appropriate subcolumn. This work-time figure represents the active time required to perform that
maintenance function at the indicated level of maintenance. If the number or complexity of the tasks within the
listed maintenance function vary at different maintenance levels, appropriate work-time figures are shown for
each level. The work-time figure represents the average time required to restore an item (assembly,
subassembly, component, module, end item, or system to a serviceable condition under typical field operating
conditions. this time includes preparation time (including any necessary disassembly/assembly time),
troubleshooting/fault location time, and quality assurance time in addition to the time required to perform the
specific tasks identified for the maintenance functions authorized in the MAC. The symbol designations for the
various maintenance levels are as follows.
1Services - Inspect, test, service, adjust, align, calibrate and/or replace.
2Fault location/troubleshooting - The process of investigating and detecting the cause of equipment malfunction. The act of
isolating a fault within a system or unit under test.
3Disassembly/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 a SMR code for the level of maintenance under consideration (i.e., identified as maintenance significant).
4Actions - Welding, grinding, riveting, straightening, facing, machining, and /or resurfacing.