External Agreement based maintenance

Hi Gurus,

My Question is about the external agreement processing in Maintenance.

Let's take the example bellow as a reference. I need to know if SAP consumes the target value (180 000) after each business closing for a maintenance order. And how we can know that the contract is no more available ( No more money to spend on the contract)

I will be very thankful, if you have a good external maintenance based agreement view explanation.

Krs,
F. Karim