I'll just stick with processing the IFS directly. One of the problems we were having was a feed file into BPCS. And, on occasion, some clown on the shop floor would enter a part into the PC based mixing package that had a 16 character item number. Which, earlier versions of BPCS only supported 15 characters. Well, when one did a CPYFRMIMPF it would hurl and it was very time consuming to find the error. Now we can post the successful ones into the posting file and leave the unsuccessful ones. The unsuccessful ones then go into a report to be handled manually.
Once you've done an IFS program, using Scott Klement's handy tutorial, it's a good tool to have in your belt.
The SQL utilized in CPYFRMIMPF and CPYTOIMPF (run them in debug!) was bizarre and probably one of the performance killers of those commands.
Those commands belong to the database team.