Reporting Options in S/4 HANA

Folks,

      I understand that FIORI is the new UI for Reporting & Dashboards for S/4 HANA.

      I also understand that SAP BW is the corporate data warehouse, recommended only if we would like to have a corporate data warehouse across multiple systems(SAP & non-SAP)

      My scenario is that I will be on SAP S/4 HANA and I would want to perform operational reporting.

      My question now is how do we now build a Operational Report in S/4 HANA , which requires consolidated information from SD, FI, and MM tables ?

     Is this case, do I build a custom ABAP report in S/4 or do I build a custom FIORI Report ?

     Would this still require me to build a HANA calculation/attribute view over the respective schema's(to consolidate information from SD, FI and MM tables)) and then expose this information for consumption in FIORI/ABAP ?

      Appreciate a clear guidance from SAP on this.

     Thanking in advance.

      Cheers,

      John