Hi Ranjan,
3.x Data staging technology is still supported in BW 7.4. However, it is highly recommended to migrate a.s.a.p. to take full advantage of the superior features of 7.x Data staging technology.
BEx 3.5 is not available anymore in BW 7.4. However, the Analytic Engine is able to execute the queries created with BEx Query Designer 3.5. Be aware that some features are not supported anymore. You can run a check tool prior to the upgrade to support an impact analysis. Report SAP_QUERY_CHECKER_740 is available for that.
Workbooks created with BEx Analyzer must be converted. The same applies to Web Templates.
Please find more information in the following SAP Notes and SAP Help:
- SAP Note 1410878 - Maintenance for BW 3.5 front-end add-ons;
- SAP Note 1807522 - BEx 3.5 Objects Migration to BEx 7.0;
- SAP Note 1911469 - Check report for discontinued query features in 7.40;
- SAP Help - BEx Runtime and BEx Tools from SAP BW 3.5 (deleted).
Best regards,
Sander