How to write an Applescript that shuts down a Drobo when a specific application quits

I have dabbled with Applescript in the past, but only in a small way, so need help this time please. I am not even sure this is possible... I have a small server cabinet with 3x Drobo, two Mac Minis and assorted 2.5" HD cases. One Drobo, at the top, is getting too hot (fans on full all day) since I installed 5x 10tb HDs. This is my backup Drobo and I use Retrospect as backup software. Retrospect runs every morning and I can set it to quit when the last backup task has completed. I would like to create a script that will activate when it sees Retrospect has quit. I would like the script to then shut down the Drobo. This is different to unmounting which would leave the Drobo powered up. Is this possible and can anyone help with such a script please? Thanks, Tom