1. Activate the subcontracting route on the Manufacturing module.

2. Go to the Inventory module > Configuration > Operation Type

3. Create a new operation, with the type Internal Transfer, and set the source location to be the picking location, and destination location to be the output location:

4. Go to the Inventory module > Configuration > Routes > Resupply Subcontractor

5. Change the current rule to the following configuration:

6. Create a new rule with the following configuration:

Make sure to set the two rules on the following order:

Now, when the user creates the PO for the trigger the subcontracting process, there will be a picking operation before the delivery: