We wound up writing a custom reporting server that Blue Prism reports to. We set Blue Prism up to send JSON data for either a ""Live Status"" or a ""Disposition"" report. In the case of the Live Status report, it just loads an action every so often saying ""Hey, I'm alive, here's what I'm doing."" We then have a page on a five-minute refresh with configurable alert times based on VM or process. If it has been longer than the configured time since we've heard from the bot, it goes red and triggers a sound. This does however, require keeping said page open.
For something a little more autonomous, you could probably run a CRON job and have it send out alerts via e-mail, text, or whatever your preferred medium is. It just might be a bit flood-prone.
John__Carter has a point about finding the root causes though. It's better to nip it in the bud early than have to be woken up at 2AM to fix something.