TM
9-4120-401-14
B - 2 . MAINTENANCE FUNCTIONS. - continued
i. Repair. The application of maintenance services1, including fault location/troubleshooting2,
removal/installation, and disassernbly/assembly3 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.
j. Overhaul. That maintenance effort (service/actions) prescribed 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 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 Il.
a. 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 item group number shall be "00."
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 4 specifies, by the listing of a work time figure in the appropriate
column 2. (For detailed explanation of these functions, see paragraph B-2.)
d. Column 4. Maintenance Level. Column 4 specifies, by the listing of a work time figure in the appropriate
subcolumn(s), the category 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
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 location 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.
C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Operator or Crew
.
O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unit
.
F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Direct Support Maintenance
H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Support Maintenance
.
D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Depot Maintenance
.
1
Services - inspect, test, service, adjust, aline, calibrate, and/or replace.
2
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).
3
Disassembly/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.
4
Actions - welding, grinding, riveting, straightening, facing, remachining, and/or resurfacing.
B-2