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 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 service- ability 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) 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.
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 with the next higher assembly. End
group item number is "00".
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 a detailed explanation of these functions, refer to paragraph B-2.
Column 4 - MAINTENANCE LEVEL. Column 4 specifies, by the listing of a work time figure in the appropriate
sub-column(s), the category 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 figures 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 (including any necessary disassembly / assembly time), troubleshooting /
fault isolation 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:
Unit (Operator or Crew)
Unit Organizational Maintenance
Direct Support Maintenance
General Support Maintenance