Hi,
i can able to achieve this by calling FM ' ME_COMPONENTS_UPDATE' twice.
one time for deleting the existing components of PR items and one more time new values
lv_rsnum = ls_eban-rsnum. "use this for comp insert
ls_vmdpm_i-ebeln = ls_vmdpm_d-ebeln = ls_eban-banfn.
ls_vmdpm_i-ebelp = ls_vmdpm_d-ebelp = ls_eban-bnfpo.
ls_vmdpm_i-rsnum = ls_vmdpm_d-rsnum = ls_eban-rsnum.
ls_vmdpm_i-sobkz = ls_vmdpm_d-sobkz = 'Q'..
ls_vmdpm_i-knttp = ls_vmdpm_d-knttp = 'Q'.
ls_vmdpm_d-updkz = 'D'.
append ls_vmdpm_d to lt_vmdpm_d.
clear ls_vmdpm_d.
call function 'ME_COMPONENTS_UPDATE' in update task
exporting
i_number = gv_preqno
tables
t_vmdpm = lt_vmdpm_d.
commit work .
* Insert new components
ls_vmdpm_i-updkz = 'I'.
append ls_vmdpm_i to lt_vmdpm_i.
clear ls_vmdpm_i.
call function 'ME_COMPONENTS_UPDATE' in update task
exporting
i_number = gv_preqno
tables
t_vmdpm = lt_vmdpm_i
t_xmdpm = lt_xmdpm
t_xmdsb = lt_xmdsb
t_mdlb = lt_mdlb.