Split Shipments and Multiple Invoices in Dynamics GP

Hi,

We have one major module to implement on split shipment and multiple invoices. I want to understand the following things

1. How the complete shipment or split shipment can be done in GP ?

2. Allocation and fulfillment of line item quantity is nothing but shipment ?

3. The same shipment /qty allocation can be transferred to invoice ?, this is nothing but multiple invoices of the order.

4. Line item Qty allocation and fulfillment (i.e. shipment )can also be done after invoice creation ?

Can anybody please explain me, what exactly the flow of Dynamics GP for shipments and invoices.

Thanks in advance.

Thanks,

Naveen