g. Install. The act of emplacing, seating, or fixing into position an item, part, or module
(component or assembly) in a manner to allow the proper functioning of an equipment or system.
h. Replace. The act of substituting a serviceable like type part, subassembly, or module
(component or assembly) for an unserviceable counterpart.
i. 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.
j. 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 condition.
k. 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
B-3. Column Entries Used in the MAC.
a. Column 1, Group Number. Column 1 lists functional group numbers, the purpose of which is to
identify components, assemblies, subassemblies, and modules with the next higher assembly.
b. Column 2, Component/Assembly. Column 2 contains the names of components, assemblies,
subassemblies, and modules for which maintenance is authorized.
c. Column 3, Maintenance Functions. 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 specifies, by the listing of a `work time' figure in
d. Column 4, Maintenance Category.
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 level of maintenance. If the number or complexity of the tasks within the listed
maintenance function varies at different maintenance levels, appropriate `work time' figures will be
shown for each level. The number of manhours specified by 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 levels are as
Operator or crew
Direct support maintenance
General support maintenance