User include structure and routines/program/user exits

Question

Hello Gurus,
     following is the step for modify the field catalog in material determination .
Modify the field catalog (OV26)
1.     Add the new field to the user include structure:
o     Header data KOMKDZ
o     Item data KOMPDZ.
2.     Add coding to the routines for assigning values to the new fields in order processing in program MV45AFZA. Use user exits:
o     USEREXIT_MOVE_FIELD_TO_KOMKD (header fields)
o     USEREXIT_MOVE_FIELD_TO_KOMPD (item fields)
3.     Add the new field to the field catalog (Customizing activity Basic Functions  Material Determination  Maintain prerequisites for material determination  Maintain field catalog).
Will you please tell me what the step 1 and step 2 mean ?  and what 's the user include structure and USEREXIT_MOVE_FIELD_TO_KOMKD/USEREXIT_MOVE_FIELD_TO_KOMPD and program MV45AFZA ?
thanks very much!

Answer 1

Hi,
KOMKD is cummunication header and KOMPD is communication item which are actually contained in KOMGD structure. So automatically when you add a field to either of header or item it becomes a part of KOMGD. And moreover KOMGD contains all the fields of KOMKD and KOMPD which are required for materail determination.
USEREXIT_MOVE_FIELD_TO_KOMKD
Use this user exit to include or assign values to additional header fields in the communication structure KOMKD taken as a basis for the material determination. This is described in detail in the section "New fields for material determination" .
USEREXIT_MOVE_FIELD_TO_KOMPD
Use this user exit to include or assign values to additional item fields in the communication structure KOMPD taken as a basis for the material determination. This is described in detail in the section "New fields for material determination ".
regards
sadhu kishore