Check out this magnificent set of service design tools. A great attempt to gather together all methods that facilitate service design projects, compiled by Roberta Tassi.
It’s made a bit too complicated by trying to simplify through cross references. But under the ‘about’ link you’ll find a ‘Tools Provenance Map”, that lays it all out in a pretty reasonable manner.
If we could utilise all this, how much nicer would the services around us be, wouldn’t they?