g. Install. Emplacement, seating, or fixing into position an item, part, or module (component or assembly) in a
manner to allow proper functioning of the equipment/system.
h. Replace. Substitution of a serviceable like-type part, subassembly, or module (component or assembly) for
an unserviceable counterpart.
Repair. Application of maintenance services (inspect, test, service, adjust, aline, calibrate, replace) or
other maintenance actions (welding, grinding, riveting, straightening, facing, remachining, or resurfacing) to restore
serviceability to an item by correcting specific damage, fault, malfunction, or failure in a part, subassembly,
module/component/assembly, and item or system. This function does not include trial and error replacement of
consumable spare type items such as fuses, lamps, or electronic tubes.
Overhaul. Periodic maintenance effort (service/action) necessary to restore an item to a completely
serviceable/operational condition as prescribed by maintenance standards (e.g., DMWR) in appropriate technical
publications. Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not
normally return an item to like-new condition.
k. Rebuild. 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 (hour, miles, etc.) considered in
classifying Army equipment/components.
B-3. EXPLANATION OF MAC COLUMN ENTRIES.
a. Group Number. This column lists group numbers, the purpose of which is to identify components,
assemblies, subassemblies and modules with the next highest assembly.
b. Component/Assembly. This column contains the noun names of components, assemblies, subassemblies,
and modules for which maintenance is authorized.
c. Maintenance Function.
This column lists the functions to be performed on the item listed in the
d. Maintenance Category. This column specifies, by the listing of a "worktime" figure in the appropriate
subcolumn(s), the lowest level of maintenance authorized to perform the function listed in the Maintenance Function
column. This figure represents the active time required to perform that maintenance function at the indicated category of
maintenance. If the number or complexity of the tasks within the listed maintenance function varies at different
maintenance categories, appropriate "worktime" figures will be shown for each category. The number of man-hours
specified by the "worktime" figure represents the average time equired 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, troubleshooting time, and quality assurance/quality control time in addition to the time required
to perform the specific tasks identified for the maintenance functions authorized in the MAC.