How to get business partner GUID of SAP user
call function 'BP_CENTRALPERSON_GET'
exporting
iv_username = iv_user_id
importing
ev_bu_partner_guid = lv_bupa_guid
exceptions
no_central_person = 1
no_business_partner = 2
no_id = 3
others = 4.
if not sy-subrc is initial.
exit.
endif.