7. 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.
8. Replace. 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.
9. Repair. 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.
The following definitions are applicable to the "repair" maintenance function:
Services -- Inspect, test, service, adjust, align, calibrate, and/or replace.
Fault location/troubleshooting -- The process of investigating and detecting the cause of
equipment malfunctioning; the act of isolating a fault within a system or Unit Under Test
Disassembly/assembly -- 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
Actions -- Welding, grinding, riveting, straightening, facing, machining, and/or
10. 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. Overhaul is normally the highest
degree of maintenance performed by the Army. Overhaul does not normally return an item to like new condition.
11. 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 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 equipment/components.
Explanation of Columns in the MAC
Column (1) -- Group Number. Column (1) lists FGC numbers, the purpose of which is to identify maintenance significant
components, assemblies, subassemblies, and modules with the Next Higher Assembly (NHA).
Column (2) -- Component/Assembly. Column (2) contains the item names of components, assemblies, subassemblies, and
modules for which maintenance is authorized.
Column (3) -- Maintenance Function. Column (3) lists the functions to be performed on the item listed in column (2). (For a
detailed explanation of these functions refer to "Maintenance Functions" outlined above.)
Column (4) -- Maintenance Level. Column (4) specifies each level of maintenance authorized to perform each function
listed in column (3), by indicating work time required (expressed as manhours 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 varies 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), troubleshooting/fault location time, and quality assurance time in addition to the time required