Design decision to create all source base GLs into HFM

Hi Team,

We want your help on the design side that whether we should create all base GLs in SAP source system into HFM or we should create many to one mapping.

Requirement from client is to do drill down from parent to base GLs which comprise the parent number so that they can analyze what is the breakup of the numbers at parent groupings . Challenge is count of SAP source base GLs is 6000 to 7000. Entity wise some base level Gls roll up to different parent. We want to know the best practice whether there will be any performance impact if all source base GLs are created in HFM or we shouldnt create all source base GLs