Root programs are called from the operating system and passed a PSB that is passed, in turn, to any called programs. The relationship with the root program is established in the JCL for batch programs or in a system definition file for online programs.
If you do not have actual JCL or System Definition files, you must create dummy ones. Analyzing the application without these files does nothing. Sample JCL and System Definition files follow:
Sample JCL file: //imsbatch JOB //S1 EXEC PGM=DFSRRC00,REGION=2048K, // PARM=(DLI,progname,psbname,7,0000,,0,,N,0,T,0,,N,,,N) //
Sample System Definition file: APPLCTN PSB=progname TRANSACT CODE=trnname