Debug Tool can be used to debug a run unit that contains a combination of Enterprise COBOL and OS/VS COBOL programs. If you want to convert your OS/VS COBOL programs, use the Convert and Compile option in the Program Preparation feature that is provided in Debug Tool Utilities and Advanced Functions.
If a run unit contains OS/VS COBOL programs that specify the COUNT compiler option or expect the FLOW runtime option, you cannot use Debug Tool to debug any programs in the run unit (including VS COBOL II, IBM COBOL, and Enterprise COBOL programs).