AP / AR Subledger to GL Reconciliation Controls Questions


I am working on putting together an SAP audit program, and need to ensure that I include controls around the reconciliation between the AP and AR subledgers and the general ledger. I know that there are reconciliation accounts setup and that a document posted in one of the subledgers will automatically be posted in the G/L, and think that this principle alone would greatly reduce the number of controls around this process. Are there instances where AP/AR transactions would not post to the subledger (and hence not post to the general ledger)?

Also, I know that the reports RFKOPO00 (A/P open items) and RFDOPO00 (A/R open items) can be run and used to reconcile the reports. How would you know that all AP and AR transactions would be reported? What types of non-reconciling items would appear in these reports and what would be the process for resolving such items?

Please let me know when you get a chance. Your help on these issues would be greatly appreciated!