The Revenue Rate is the rate used to automatically calculate the Billable Amount.
In the Administration workspace, Setup tab, Billing Advanced Attributes popup, the user can select one of the following Revenue Rate Sources to define this rate:
Global.Project – The rate depends entirely on the Project Revenue Rate entered upon selecting this option.
Global.Resource – The rate depends entirely on the assigned Resources.
Global.Job Classification – The rate depends on the Job Classification identified for each assignment (if no specific Job is identified, the assigned Resource rate will be considered).
Project.Resource – The Project Manager can define a rate specific to each Resource within the Project.
Project.Job Classification – The Project Manager can define a rate specific to each Job Classification within the Project.
Note that the Billable Amount calculated as described above can be overwritten manually for each Task, while the As of Date of the Revenues can be changed (by default the Finish date of the Task) using the Billing Date field for each Task.