Enhancement package upgrade

Dear all,

We are planning to upgrade the SAP ERP system Enhancement Package6 in ECC6.0 ERP system.

Source ERP: ECC6.0

Target verions: ECC EHP6

1) Is there any impact of other environments[BI, PI, & Solman] depend on level of applied EHP6 Version in ERP system.?

2) Is there any impact in design of connection with other SAP system like Connecitivity to the SAP solution Manager sytem ,Centralized user management, PI system?

3) Is it necessary to upgrade the (ST/PI, API) in Solution manager ?

Thanks Thiru.