Hi Mack
i have no great expertise in this area, but can provide few pointers
You have the option of posting into Internal orders or direct into COPA... IO are to be used if you expect lot of stuff to be posted related to 1 contract or service order in CRM... Later on, you settle the IO to COPA, if you wish... The settlement profile in ECC system should allow PSG as settlement receiver.. Then you can maintain settlement rule for PSG in the ECC
However, if for each service order in CRM, you expect only one posting upon billing, then make the posting directly into COPA, instead of IO
Br, Ajay M