ARMY TM 9-2815-256-24 AIR FORCE TO 38G1-96-2 MARINE CORPS TM 2815-24/5 APPENDIX B MAINTENANCE ALLOCATION CHART Section I.  INTRODUCTION B-1  THE ARMY MAINTENANCE SYSTEM MAC . a. This introduction (section I) provides a general explanation of all maintenance and repair functions authorized at various maintenance levels under the standard Army Maintenance System concept. b. The  Maintenance  Allocation  Chart  (MAC)  in  section  II  designates  overall  authority  and  responsibility  for  the performance  of  maintenance  functions  on  the  identified  end  item  or  component.    The  application  of  the  maintenance functions  to  the  end  item  or  component  will  be  consistent  with  the  capacities  and  capabilities  of  the  designated maintenance levels, which are shown in the MAC in column (4) as: Unit - includes two subcolumns, C (operator/crew) and O (unit) maintenance. Direct Support - includes an F subcolumn. General Support - includes an H subcolumn. Depot - includes an D subcolumn. c. Section  III  lists  the  tools  and  test  equipment  (both  special  tools  and  common  tools  sets)  required  for  each maintenance function as referenced from section II. d. Section IV contains supplemental instructions and explanatory notes for a particular maintenance function. B-2    MAINTENANCE  FUNCTIONS.    MAINTENANCE  FUNCTIONS  WILL  BE  LIMITED  TO  AND  DEFINED  AS FOLLOWS: a. Inspect.    To  determine  the  serviceability  of  an  item  by  comparing  its  physical,  mechanical,  and/or  electrical characteristics with established standards through examination (i.  e.  , by sight, sound, or feel). b. Test.  To verify serviceability by measuring the mechanical or electrical characteristics of an item and comparing those characteristics with prescribed standards. c. Service.  Operations required periodically to keep an item in proper operating condition, i.  e.  , to clean (includes decontamination, when required), to preserve, to paint, or to replenish fuel, lubricants, chemical fluids, or gases. d. Adjust.  To maintain or regulate, within prescribed limits, by bringing into proper or exact position, or by setting the operating characteristics to specified parameters. e. Aline.  To adjust specified variable elements of an item to bring about optimum or desired performance. f. Calibrate.  To determine and cause corrections to be made or to be adjusted on instruments or test, measuring, and diagnostic equipment 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 compared. 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. B-1