Steps and Issues in upgrading SEM-BCS Ver 4 to SEM-BCS 6

Hi Experts,

Planning to make system copy of existing BW 3.5 with SEM-BCS ver 4 objects and then upgrade BCS to ver. 6. Aware that, BCS ver 6 needs only BI 7.0.

Could any of the experts help me by providing the steps need to follow for a smooth migration? Also, could you highlight issues which may arise during migration particularly on BW 3.5 to BI 7.0 as well as when upgrading BCS.

Thanks with regards

Ram