Report cookbook
The one rule that keeps interval reports honest, and worked examples as reports ship.
Filter by object, then field, then value#
Every interval belongs to one Tracked object and one Tracked field. Before you group by Value, filter or group by Tracked object and then Tracked field. A grouping that mixes fields adds Status minutes to Owner minutes, and the totals stop meaning anything.
Worked examples for time in status, time per owner, and hours per case arrive with the packaged reports.