B-2. Maintenance Functions (cont'd)
f. Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test,
measuring and diagnostic equipment used in precision measurement. Consists of comparisons of two
instruments, one of which is a certified standard of known accuracy, to detect and adjust any discrepancy in
the accuracy of the instrument being compared.
g. Remove/Install. To remove and install the same item when required to perform service or other
maintenance functions. Install may be an act of emplacing, seating or fixing into position a spare, repair part
or module (component or assembly) in a manner to allow proper functioning of an equipment or system.
h. Replace. To remove an unserviceable item and install a serviceable counterpart in its place. "Replace" is
authorized by the MAC and is shown as the 3rd position of the SMR code.
Repair. The application of maintenance services, including fault location/troubleshooting, 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.
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.
k. Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to
alike 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 measurement (hours/miles, etc.) considered in classifying Army equipment/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 items listed in
column 2. (For detailed explanation of the items listed in column 2, 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 times will be shown for each category.