Most of my line items are service related jobs, some of them involve inventory. In order for me to receive payment, the customer needs to sign the shipment order. But the thing is most of the time the jobs that are supposed to be done are not the same as the customer's initial purchase order, and I would have to amend the shipment orders after the customer revises their purchase order. 

My understanding in SAGE 300 ERP is that you are unable to print a shipping order without actually allocating the quantity shipped.

I have come up with this "procedure". Are there any downsides to using this method? Other than the inaccurate inventory quantities until the order is invoiced? 

1. I have 10 items in my OE number 0001, based on customer PO.
2. In my shipment I select OE 0001 as my order number, and I post the shipment as SH 0001 without shipping any items.*
3. The customer makes an amendment to their PO at this time, and I create a new OE 0002 based on that PO Version 2.
4. PO Version 2 has a totally different line item and quantities of 20. 
5. In my shipment I select OE 0002 as my order number, and I post this shipment as SH 0002 without shipping any items.*
6. SH 0002 is the correct shipment document that is signed by my customer.
   
7. I create an INVOICE with SH 0001 and SH 0002, and both line items from both SH will appear in the invoice. At this point, I can manually key in the “Qty. Invoiced” values, and post this invoice. In this example I would manually input 0 for the first item from SH 0001, and input 20 for the item from SH 0002. 

*Shipment report will be amended to reflect quantity ordered instead of quantity shipped, so it prints "correctly".