BW is utilized by both SAP R/3 and SRM independently as the enterprise analytics solution. BW provides standard content for both the various SRM components(EBP, SUS, Bidding Engine, etc) and the SAP R/3 modules(MM, FI, etc). Based on the release of SRM and BW, different content and reports are available for use. In SRM –- especially EBP -- SAP has provided different content that can be used based on the scenario implemented (Classic, Extended Classic, or Standalone). Companies that use both SRM and SAP R/3 have integrated BW to both systems as well in many cases.
Take a look at the links below which will give you a good amount of detail on SRM:
Dig Deeper on SAP ERP software
An SAP SRM user is looking to update an SRM URL process when implementing or changing a catalog in a live environment in SAP SRM.
An SAP SRM user wants to know how to set Confirmation and Invoice as the default options in a limit-order shopping cart.
Configuring WF for SAP SRM in the extended classic scenario