In order to forecast migration time, you have to take several influencing factors into account:
Hardware requirements must be fulfilled according to the ARIS System Requirements (see ARIS System Requirements.pdf on DVD, ARIS Download Center or Empower)
When backing up tenant data, all data is saved in one tenant archive file. It is plain to see, the bigger the file the longer migration will take.
The time needed for restoring an ARIS database in ARIS 9 can be roughly multiplied by 1.5 up to 3 in ARIS 10. If this takes, for example, 30 minutes, migration can take from 45 to 90 minutes. If the size of all ARIS databases together is bigger than 3 GB, the restore tenant action can take longer than 24 hours. This large size can occur because of a high number of databases, documents stored in ARIS document storage. In this case migrate tenant data having all databases excluded, and migrate the databases manually.