Decommission / Sunset of SRM system

Hi experts,

My client has a plan to de-commission the SRM 7.0 system from the business. we are in the process of impact analysis in transaction data's, master data's and also archiving of all SRM documents in ECC after sunset of SRM.

Please can anyone share their experience//expertise in this area-Decommissioning of SRM 7.0?

Also, Pl help provide SAP 's key recommendations fur such scenarios //Notes etc

Inputs greatly appreciated.

with regards,

Deivakaniraja r