what are the steps involved in SAP BI report authorization check.

Ex: In Ecc, when a Transaction code is executed, system check if its valid tcode or not in TSTC and then goes on checking if its locked or not, then su24 comes in to play. Similar fashion, how does a report gets checked in SAP BI. How does system know that it should look for S_RS_COMP/ S_RS_COMP1 or S_RS_AUTH for data authorization check.