Your SAP S/4HANA Server system consists of an ABAP Central Services instance, a Primary Application...

For an SAP S/4HANA Server system consisting of an ABAP Central Services (ASCS) instance, a Primary Application Server (PAS) instance, and two Additional Application Server (AAS) instances, a total of 5 system profile files are evaluated during a complete system start. This includes the START profile for each of the 4 instances (1 ASCS, 1 PAS, and 2 AAS) and 1 DEFAULT or INSTANCE profile that is shared across the system. Each instance reads its own START profile, while the DEFAULT or INSTANCE profile contains parameters that apply to the entire system.