As simply as you determine the workload for a project within Popsiplan®, we can consider the cost total of a project as of its creation. This cost calculated according to  the cost average job is then posted on a cumulative graph.
As soon as  Timesheets are indicated, we calculate the real project cost which we post on the planned graph. In short, as long as the red curve (real) is under the green curve (estimated) all is well.