Number of Oracle online redolog groups

Hi

Currently we have 4 groups of Oracle Redo LOGFILES with 2 members each 50 MB as standard installation

Our DBA team wants to increase with 10 Groups 3 members each100 MB.

I want to know if there is any guide line or standard there on setting up number and size of redo log files from SAP.

Your reply will be highly appreciated

Thanks

-Al