There are situations where it is preferable to prepare the device explicitly before the installation and resume operation explicitly after the installation. The PrepareForUpdateStateMachine, which is described in 8.4.8 can be used for this task.
This can be the case, when several devices of a machine should be updated at once. All devices have to be prepared first to ensure that all are waiting for an update. After that they can be updated by the Client. At the end after all individual updates are complete the devices can resume operation.
Or a device requires the behavior to enter a safe state (e.g., reaching a safe area) to be able to update the software.
If the installation comprises several steps (e.g., backup parameters, install firmware, restore parameters). The steps can be encapsulated by the Prepare and Resume Methods to ensure consistency between all the steps.