Ah but this was pre-systemd so you would have been screwing around trying to find whatever script was being used to lock the doors after close of business.
Well it's IRIX, so you'd just create a little bourne shell script in /etc/init.d, with symlinks from e.g. /etc/rc2.d to start/kill it on the respective run levels.
This was a pretty critical system though so why not just place this particular program inside /etc/inittab ?
