In order to delete devices from the asset inventory, select the devices you want to delete with a left mouse click. You can select multiple devices by using Shift-Left Click or Ctrl-Left Click.
After you have clicked on "Remove", the devices you have selected will not be completely deleted from the inventory but will have been set to the Decommissioned stage. This allows you to re-visit the configuration of decommissioned devices if need be.
In order to list decommissioned devices in the inventory, open the Scope pane and check the "Decommissioned" box. If you only want to see decommissioned devices, enter "DEC" in the Stage filter field, or uncheck all other stages in the Scope pane.
You permanently delete a device from the inventory once that it is decommissioned by removing the device once again. Any device data will then be gone, and the slot in your license pool is freed up for other devices.