It is completely based on the connection settings IDT
1) If you use User name and pwd in the Connection IDT:
If you CPIC ID/PWD in the connection perameters, allways CPIC ID will bring the data from the BW.
All the users ( WInAD/Enterpsie/.. ) who have access to these reports can refresh the report and get the Data from BW. ( CPIC ID Will be used for retriving data from BW)
2) If you use SSO in the Connection IDT:
In this case you will not be giving user ID and PWd in the connection. Just you will use SSO.
All the users will be having there own IDs in the BO and BW.
BO IDs and BW IDs are linked with aliasing. Allways respective user's BW ID will be fetchcing data from BW.
In this Users should have access on the BW side as well as BO Side. It will fail, if he dont have access on any one of them.
Hope this answers your question. Let me know if you need any further information.
Please Refer to this link for detailed information on setup SSO against SAP BW with SAP BO BI4.0 Common Semantic Layer (UNX) or BICS.
SNC in BI4.0 is used for SSO to BW for non-SAP users (Windows AD, LDAP users) for UNV universe (legacy semantic layer). For the new semantic layer (UNX) in BI4.0,SNC is used only for securing communication but not for authentication. The authentication piece will be handled by the Secure Token Service (STS). Therefore, if you do not need secure communication you do not need to use SNC.
Links to SNC setup and troubleshooting (same setup as BOE 3.x – no change)
http://wiki.sdn.sap.com/wiki/display/BOBJ/How+to+setup+XI3.1+WebIntelligence+SSO+with+SAP+BW