TM-6115-634-14&P NAVFAC  P-8-647-14&P T0-35C2-3-445-14 TM-6115-14&P/1 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 in- cludes the act of returning to zero those age measurements (hours/miles, etc.) considered in classifying Army equipment/components. 6-3. 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 mainte- nance  significant  components,  assem- blies, 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 compo- nents,  assemblies,  subassemblies  and modules for which maintenance is authorized. c. Column 3, Maintenance Function. Column 3 lists the functions to be per- formed 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 (by listing of a work time figure in the appropriate subcol- B-2 umn(s)), the level of maintenance au- thorized to perform the function listed in Column 3. This 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 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 service- able condition under typical field oper- ating conditions. This time includes preparation  time  (including  any  necessary disassembly/assembly  time),  troubleshoot- ing/fault location time and quality assurance/quality control time; in addi- tion, to the time required to perform the specific tasks identified for the maintenance  functions  authorized  in  the maintenance  allocation  chart. The  symbol designations  for  the  various  maintenance levels are as follows: C . . . . . O . . . . . F . . . . . H . . . . . L . . . . . D . . . . . Operator or Crew Unit  Maintenance Intermediate  Direct  Support Maintenance Intermediate  General  Support Maintenance Specialized  Repair  Activity (SRA) Depot  Maintenance e. Column 5, Tools and Equipment. Column 5 specifies,   by code, those common tool sets (not individual tools) and special tools, TMDE and support equipment required to perform the designated func- tion. f. Column 6, Remarks. This column shall, when applicable, contain a letter code, in alphabetic order, which shall be keyed to the remarks contained in Section  IV.