Yes Paulo,
I understand the document legality aspect of intercompany billing and will have corresponding cost and revenue recognized in alignment with documents.
In nutshell you are recommending following.
1. Create a Global project with WBS elements for each company code.
2. Have time and costs booked by Colombian employees in WBS associated with their company code (Colombia).
3. Have a RRB triggered at actual costs +% based from Colombian company code WBS to US company code WBS.
4. Recognize this billing as cost against PO raised from US company code to Colombian company code.
5. Once all costs are recognized, trigger RRB to customer.
Is above correct? If so, this doesn't require use of Intercompany line items (1005) in DIP profile as source. This is regular PO-SO scenario between intercompany billings.
The time by employees (of US and CO) should be booked similarly in US project. No need to track it separately on a Colombian WBS. We have real time CO-FI integration.
When CO employee books time against US WBS in controlling, system automatically posts the intercompany charges & Time.