Actually, mixing calls between OPM and ILE COBOL programs can be fairly easy. If you expect to call an ILE program, use 'EXIT PROGRAM AND CONTINUE RUN UNIT.' This allows the called ILE program to be used by either an OPM or ILE program. Parameters in the linkage area are passed back and forth. Since the called ILE program is still running, the next time it is entered the WORKING-STORAGE DIVISION contains the last settings. All files are still opened. There are other options that provide additional object control and you can find them described in the ILE CONCEPTS and COBOL manuals.