This is useful only between (nearly) identical systems.
Use
mksysb
to create a bootable image of the source system, e.g to tape.
Ensure the latest
firmware level on the target machine, depending on the chosen methods one may perform
firmware upgrades along with some of the following tasks.
Connect Terminal/Keyboard.
If not yet in SMS mode, reset or power down/up,
and during boot press key "1" (serial console) or "F1" (graphic console).
Use SMS menus to select boot from tape.
Proceed as suggested.
Note, however, that the target system is identical copy of the "source"
system, it has, e.g., the same IP host name and address.
Hence it must be avoided to have both online at the same time.
After installation is complete,
check/set the proper bootlist
bootlist -m normal -o
bootlist -m normal -o hdisk0 hdisk1 # e.g. for a mirrored system