Tuning systems to alleviate decreased month end close performance after upgrading to R12 Subledger Accounting from 11i. Reducing Create Accounting completion time by 97% and reducing archivelog generation by 58%. In R12, the Create Accounting Program, GMFAACCP, would stall our production EBS. We were able to decrease the Create Accounting Program for OPM Production Subledger run-time from an original 22 hours to an average of 30 minutes. This was accomplished by modifying: huge pages, SGA, DBWr processes, subledger processor defaults and indexes. These actions compressed our period close process, saving an entire day.