You entire comment is monstrous bigotry of the modern. The B-2 was in fact the first large, complex product ever built entirely from a CAD database - a factor in its huge cost.
As a CIM Manager for a major B-2 subcontractor, I can assure you they knew what they were doing. Yes, even 30-35 years ago. Yes, they knew as much or more then than we know today about BOMs, manufacturing, CAD, digital records and archiving, documentation and configuration management, and everything else. (BOMs weren't in SAP, but they were in mainframe DBs, ERP systems, and CAD systems, some of which are still sold and used today.) I have literally never worked on any other program in my entire career that was as well-run and orchestrated overall as the B-2 program. (We called it ADP-101 at the time, and for the first few years, we didn't even know what we were working on!)
As a CIM Manager for a major B-2 subcontractor, I can assure you they knew what they were doing. Yes, even 30-35 years ago. Yes, they knew as much or more then than we know today about BOMs, manufacturing, CAD, digital records and archiving, documentation and configuration management, and everything else. (BOMs weren't in SAP, but they were in mainframe DBs, ERP systems, and CAD systems, some of which are still sold and used today.) I have literally never worked on any other program in my entire career that was as well-run and orchestrated overall as the B-2 program. (We called it ADP-101 at the time, and for the first few years, we didn't even know what we were working on!)