f. Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test, measuring, and
diagnostic equipments 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
g. Remove / Install. To remove and install the same item when required to perform service or other maintenance
functions. Install may be the act of emplacing, seating, or fixing into position a spare, repair part, or module (component or
assembly) in a manner to allow the 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 code of the SMR code.
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/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 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.
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 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 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
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.