ECC-HR has multiple busniess units but in SRM only few replicated

Hello experts,

am having few questions on HR replciation from ECC to SRM.

We replicated org structure from ECC- HR in SRM system now scenario is :

In ECC-HR Org has multiple business units but we implemented SRM only for specific business units,when we ran change pointers, IDOCs are created for all changes of all business units and these IDOCs are failing in SRM.

Now please guide me if i run RHALEINI only in Update mode and entered specific org units. In selection screen.Will it work.....i read somewhere,it may replace the values of the attributes or something can be broken out in org structure,If i run RHALEINI in update mode than what are the testings i need to perform before doing this actually in production system ?

When i run RHALEINI in update mode,actually replciate those changes in SRM system do i need to run RBDMIDOC or any other report ?

Smriti