There's a bit about Xcom in here.
http://www.gdcvault.com/play/1018058/AI-Postmortems-Assassin-s-Creed
Mr. Mark any other references like this or where or what search terms I can use to find more?
You might want to take a look into goal oriented action planners.
I took a look at one tutorial... it's interesting. I need to see if it can deal with multiple goals and/or whip something up to give it some overall tactical coherency. But its very interesting.