splitting HR and payroll from the R/3 instance

Our technical teams have been asked by management to explore the feasibility of splitting (decoupling) HR and Payroll (HR/Pay) from our existing Core R/3 landscape; most likely as part of our upgrade from 4.6C to SAP ERP 7. We met internally, and had more questions than answers. There is also very little in either the SDN or ASUG discussion forums on this subject, and nothing current.

From a technical perspective (our business/functional side is also looking into this), we would like to know …

• Why other SAP customers have implemented separate HR/Pay and FI, etc, systems? What benefit does it provide?

• Have other customers split HR/Pay off of an existing R/3 system? What were the technical benefits of splitting?

• What is the degree interdependence/independence between HR/Pay and the remaining core system?

• Is a Master Data Management Server (MDMS) needed or recommended?

• How are system management activities (e.g., support packs, disaster recovery, etc) affected by the split?

• How many full time equivalent (FTE) team members are needed to support ALE?

• Does a split between HR/Pay and FI/CO, etc, introduce any archiving issues?

• Since this is being suggested as part of our upgrade, if we split, should we do it before, during, or after the upgrade?

I realize this is a big question – actually several questions. I appreciate any experience, advice, etc, anyone can share.

Thanks in advance,

Dave