ARMY TM 9-2815-259-24 AIR FORCE TO 38G1-125-2 MARINE CORPS 09249A/09246A-24 B-2 MAINTENANCE ALLOCATION CHART (Continued) 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 assigned maintenance level is shown as the 3rd position code of the SMR code. i. Repair. The application of maintenance services¹ including fault location/troubleshooting², removal/installation, and disassembly/assembly³ procedures, and maintenance actions⁴ 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 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. 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. b. Column 2,  Component/Assembly.   Column 2 contains the item 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 Level.  Column 4 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 figure will 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 (condition/follow-on tasks)   (including any necessary disassembly / assembly time), troubleshooting / fault location time, and quality assurance time in addition to the time required to perform the specific