@raphrf Hi Ralph, could you explain what the confusion is in a little more detail? What are you currently doing in your process? Are you defining the progress billing base at the task level? If so, could you help me understand why? do tasks get billed differently (i.e. amount vs. quantity) on the same project? 

typically, i try to avoid adding details at the task level because it becomes a maintenance issue but in some cases, it’s necessary (i.e. defining subaccounts or something along those lines)

also, in my experience, i manage the project billing base at the project level, not the task level since typically the whole project is billed the same way

@raphrf   Great question.  If you populate on the Task tab of the project, when adding a new line on the budget, this field will auto populate with the base identified on the task.   

The base on the Revenue budget will determine which columns can be updated for billing - If your billing base = quantity then Pending Invoice Quantity will be available for editing and Pending Invoice Amount will not be editable.  If you have the base = amount, then Pending Invoice Amount is editable but Pending Invoice Quantity is not.  

I hope this helps.

We have change orders enabled and we like to use them. We are currently using the Revised Revenue Budget for our WIPs, so we want this amount to be representative and up to date.

We have analyzed the option of using the progress billing base type in quantity mode but have encountered some blockers.

QUANTITY mode uses the unit rate for billing as written in this article

We notice that when we make a Change order on a task, its Revised Revenue Budget is correctly updated to the CO Release, which is OK for WIPs.
However, due to the photo below, the unit Rate is not refreshed by the CO, and now the invoice that will be generated in Quantity mode will be incorrect. Is it us who are using the change order incorrectly with the quantity mode?

example my original project unit rate is 1000, I make a change order and I indicate a unit rate of 500, the revised budgeted amount will become 1500, but the unit rate will remain at 1000. if my progress billing base is in amount mode my invoice will come out with the correct amount of 1500, but if it is in quantity the invoice will still be 1000.