WOW, I would note like to do this from scratch either. I do not have a doc, but How much detail do they want, is the purpose of the document for them to manage the alarms, isn't that what a support contract is for?
I would personally get the person who looks after the kit on site on a training course, then they would have an understanding of how to resolve alarms.
But if you do end up doing it good luck and if you need any help, I don't mind getting involved.