Letter of Guarantee Value not Updating with Payments

Question

Dear Expert
The requirement from the user is that when a payment is made , the system should deduct the amount paid and refresh the new available value for the customer.
For Example : A Financial document is created with 1000 value . And Sales order created for 8000 . Therefore now the open value is 2000. This means that the customer can order goods worth 2000 only.
In the meanwhile the first order is delivered and billed . And the customer has paid 8000 when he received the bill. this means that now he has paid so he can now order more goods worth 8000.
but in the system it still shows open value as 2000 , although now that the customer has paid, it should be updated with the payments made so the value can be used by the customer that he had paid.
If any of you has any idea how to tackle this ( it works same way in credit management ) but not in financial documents.
we were thinking of another work around , i.e by closing the Financial document that has been paid and creating a new one by adding the remaining balance. i.e 2000+ 8000 , this way the customer can again use his value. but then how can we automate the system to alert the sales user that the payment has been made for a certain invoice for a certain LG.
your idea's and suggestion are highly welcome
Best regards,

Answer 1

Dear ATGSD,
The functionality in GTS is designed for modelling of a single financial document for which the initial value is not updated.
I understand your user's requirement, but surely that is dealt with simply by setting a credit limit in the SAP ERP system?  There should be no need to use the GTS functionality at all.  In the ERP system, the credit limit is updated by the account payments, exactly as your user requires.
Please let us know if that would work, or if there are more detailed requirements that are not apparent from your post - thanks.
Regards,
Dave