Bill Of Service Service Entry sheet

Dear All,

I have this scenario and i need your help.

I am using the Cycle for BOS with Service Entry sheet.

for example :

I have one line item with multiple service line. one of them for example has 5 Qty with value 1000.

after that, i will create service entry sheet for 3 Qty of the 5 Qty and the value will be 1000 not changed however the service completeness is 70%.

so i need to invoice 70% of the 3 qty value and will remain 30% of the quantity to be invoiced later besides the 100% for the remaining 2 qty.

it is like creating billing plan for service entry sheet.

can anyone help me to solve this scenario.

thanks