Abstract: A device, such as a mobile phone, comprises a management tree store (101) which stores an Open Mobile Alliance Device Management (OMA DM) management tree. A tree processor (103) is arranged to detect a change associated with at least a first node of the management tree. A backup node processor (107) adds a first backup node as a child node of the first node in response to the detection of the change. The backup node comprises backup data representing a setting for the first node prior to the change. A restore processor (109) is arranged to restore at least part of the management tree to a setting prior to the change in response to a retrieval of the backup data from the first backup node. The invention may facilitate/improve backup and restore operations for OMA DM devices.