Explanation of Columns In the MAC - TM-5-4120-393-140295

TM 5-4120-393-14

B-2. MAINTENANCE FUNCTIONS. - Continued.

i. Repair. The application of maintenance services , including fault location/trouble-shooting , removal/ installation,

and disassembly/assembly procedures, and maintenance actions 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 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.

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 equipments/components.

B-3. Explanation of Columns In the MAC, Section II.

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 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.)

d. Column 4, Maintenance Category. 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.

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 SM R code) for the

category of maintenance under consideration.

Actions - welding, grinding, riveting, straightening, facing, remachinery, and/or resurfacing.

B-2