Marking progress top-down and bottom-up

There are two methods of working when assigning progress: you can report progress either using estimates of the completed duration, duration percentage complete or overall percentage complete of a task, or using estimates of the amount of a resource or cost allocation that has been completed. For example:

If you know that 2 days, 10% of the duration of a task, or 20% of the task overall has been completed, you can assign that progress to the task and the progress is reflected across any allocations on that task (this is the top-down method).
If you know that 200 units of a work-based resource allocation or £2000 of a cost allocation have been completed, you can assign progress to the allocations and determine the task's progress from the progress to its allocations (this is the bottom-up method).

If you model tasks in terms of task work, you can also report progress using estimates of the completed task work that has been completed against a task.