Replace. The act of substituting of a serviceable like type part, subassembly, or
module (component or assembly) for an unserviceable counterpart.
Repair. The application of maintenance services or other maintenance actions to
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.
Overhaul. That maintenance effort (service/action) necessary to restore an item to a
completely serviceable/operational condition as prescribed 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
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 materiel 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 equipments/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 components, assemblies, subassemblies, and modules with the
next higher assembly.
Column 2. Component/Assembly. Column 2 contains the 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 Category. Column 4 specifies, by the listing of a work time
figure in the appropriate subcolumn(s), the lowest level of maintenance authorized to perform
the function listed in Column 3. 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 vary at different maintenance categories,
appropriate work time figure will be shown for each category. 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, 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 maintenance allocation chart. The symbol designations for the
various maintenance categories are as follows:
Operator or crew.
Direct support maintenance.
General support maintenance.
Column 5. Tools and Equipment. Column 5 specifies by code those common tool sets
(not individual tools) and special tools, TMDE, and support equipment required to perform the