Internal Orders are two types. 1. Real and 2. Statistical.
Real orders get real postings and statistical orders get statistical.
Statistical means information purpose only.
Statistical orders cannot be settled.
At the time of postings to cost elements you must have at least one real object.
If you give more than one real object, read the following:
When you two real objects like cost center and WBS element at the time of posting a journal voucher, the WBS element prevails as a real object and the two statistcal postings will be posted. One to cost center and the second one to the profit center assigned in the WBS element.