Invoice creation, only upon complete delivery

Hi All,

I'm working on a scenario in SD and I would appreciate your help on this.

Scenario:

There will be a Z/Custom field and user will select/check that, upon selection of that field I need one invoice, only upon complete delivery of all the line items. This process should work for all scenarios like Order to cash, Third party Sales, Individual Purchase Order.

In a nutshell, SD Invoice creation should happen only when all the line items have been completely delivered. As far as, SD process is concerned we can probably find out from delivery status, but where do we get the information on complete delivery status for Third party Sales?

Thanks in advance.