The current inter company function is as follows.
(Blues comnany and green company are linked in inter company functions.)

Step.1. User creates sales order A from customer in blue company
Step.2. Requistion Worksheet in blue company
Step.3. System creates purchase order B to green company in blue company
Step.4. Intercompany Function sends purchase order to green company
Step.5. System creates sales order C from blue company in green company
Step.6. Requistion Worksheet in green company
Step.7. System creates purchase order D to vendor in green company
Step.8. User posts purchase order D in green company
Step.9. User posts sales order C in green company
Step.10. Intercompany Function creates purchase invoice E even if purchase order B exists.

User is confused whether post purchase invoice E or post purchase order B.
(As a workaround ,it's better to post B and delete E...)

However, I think that this scenario itself is very universal.
I hope that the following scenarios can be realized by posting automatically intercompany purchase order.

Step.1. User creates sales order A from customer in blue company
Step.2. RequistionWorkSheet in blue company
Step.3. System creates purchase order B to selling company in blue company
Step.4. IntercompanyFunction sends purchase order to green company in
Step.5. System creates sales order C from purchasing company in green company
Step.6. RequistionWorkSheet in green company
Step.7. System creates purchase order D to vendor in green company
Step.8. User posts purchase order D in green company
Step.9. User posts sales order C in green company
Step.10. Intercompany Function post purchase order B.
Step.11. User posts sales order A.

Regards,