Why some data cannot be archived

The following types of data cannot be archived:

Data from a project from which data is currently booked out.
Items that are currently appearing in timesheets.

For this reason, you cannot archive charts or summary groups that contain items of this type. This should not be an issue, as you will normally only want to archive data that relates to past activities that are completed. If an item of data is currently booked out or is currently appearing in timesheets, it can normally be considered to be recent, active data that you should not be archiving.

In addition to this, you cannot archive any branch of a project that contains an archived chart or summary group. For this reason, it is good practice to archive data at as high a level as possible in the project hierarchy.