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 third position code of the Source, Maintenance, and Recoverability (SMR) code.
The application of maintenance services including fault location/troubleshooting, removal/ installation, 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.
Maintenance services include inspection , testing, service, adjustment, alignment, calibration, and/or
replacement. Troubleshooting is 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). Disassembly
is the step-by-step breakdown (taking apart) of a spare functional group coded item to the level of
its least component that is assigned an SMR code for the level of maintenance under consideration
(i.e., identified as maintenance significant). Maintenance actions include welding, grinding, riveting,
straightening, facing, machining, and/or resurfacing.
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., Depot Maintenance Work Requirement). Overhaul
is normally the highest degree of maintenance performed by the Army. Overhaul does not normally return an item to like-new
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 materiel maintenance applied to Army equipment. The
rebuild operation includes the act of returning to zero those age measurements (e.g., hours/miles) considered in classifying Army
Explanation of Columns in the MAC
Column 1, Group Number
This 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
This contains the item names of components, assemblies, subassemblies, and modules for which maintenance is authorized.
Column 3, Maintenance Function
This lists the functions to be performed on the item listed in column 2. (A explanation of these functions appears above.)
Column 4, Maintenance Level
This specifies each level of maintenance authorized to perform each function listed in column 3 by indicating work-time required
(expressed as man-hours 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 level 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), fault location/troubleshooting time, and quality assurance time in
addition to the time required to perform the specific tasks identified for the maintenance functions authorized in the MAC. The