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:
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