Replace. To remove an unserviceable item and install a serviceable counterpart in its place. Replace is
authorized by the MAC and assigned maintenance level is shown as the 3d position code of the SMR code.
removal/installation, and disassemblylassembly3 procedures, and maintenance actions4 to identify troubles and 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) 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 new condition.
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.
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 Level. Column 4 specifies each level of maintenance authorized to perform each
function listed in Column 3, by indicating work time required (expressed as manhours in whole hours or decimals) in the
appropriate subcolumn. This work-time 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 levels, appropriate work-time figures are to be shown for each level. 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 location time, and quality assurance 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:
C..............................................Operator or crew maintenance
O .............................................Unit maintenance
F ..............................................Direct support maintenance
Services - inspect, test, service, adjust, aline, calibrate, and/or replace.
Fault locate/troubleshoot - The process of investigating and detecting the cause of equipment malfunctioning; the act of
isolating a fault within a system or unit under test (UUT).
Disassemble/assemble - encompasses the step-by-step taking apart (or breakdown) of a spare/functional group coded
item to the level of its least componency identified as maintenance significant (i.e., assigned an SMR code) for the
category of maintenance under consideration. Services - inspect, test, service, adjust, aline, calibrate, and/or replace.
Actions - welding, grinding, riveting, straightening, facing, remachinery, and/or resurfacing.