TM 55-8115-203-23 & P
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 (inspect, test, service, adjust, align, calibrate, or replace) or
other maintenance actions (welding, grinding, riveting, straightening, facing, re-machining, or resurfacing) to restore
serviceability to an item by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module
(component or assembly), and item or system.
j. Overhaul. That maintenance effort (services/actions) necessary to restore an item to a completely
serviceable/operational condition as prescribed by maintenance standards (i.e., 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. 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 included the act of returning to zero those age
measurements (hours/miles, etc.) considered in classifying Army equipments/components.
B-3. Column Entries Used in the MAC.
a. Column 1, Group Number. Column 1 lists 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 name of components, assemblies, subassemblies
and modules for which maintenance is authorized.
c. Column 3, Maintenance Functions. Column 2 lists the functions to be performed on the item listed in column 2.
(For detailed explanation of these functions, see para B-2).
d. Column 4, Maintenance Level. Column 4 specified, 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 the 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 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 followed: