ERNI was a dispatch overlay. I've seen it used on circle W, big O, Composites, etc..
And since it is an overlay it is designed to tie into all the controls listed above, which means that each job is basically a one of a kind.
Knowing the theory of operation is one thing. Having the original job prints is crucial on this, of for that matter, any Overlay.(IMHO)..Might be worth biting the bullet, and contacting Big O about purchasing the original job prints.