Which Objects Can Be Confirmed? 

You can enter completion confirmations for:

As costing, scheduling, and capacity requirements planning is only carried out on the basis of the confirmation data of the phases, only phases and not operations can be confirmed. At present, an operation is not automatically confirmed when you confirm its phases.

Make sure that you assign material components for which backflushing has been defined to phases only. When the respective phase is confirmed, the goods issue for this component is posted.

For information on the confirmation of phases and secondary resource, see R/3 Integration Using Process Messages.