There can be interface with 3rd party tools if there is portal you can have a eform- the manager/HR fills in form the data will be interfaced using PI/XI.
Or there can be outbound interface with all required fields you can include benefits infotype also here - logic for the extraction should be from respective infotype - XI will interact with 3rd party.
From 3rd party there will inbound file which update required infotypes.
Thanks