On the website of The Systems Thinker you will find a very interesting article about the basics of causal loop diagrams.
The article is written by COLLEEN LANNON.
She is using an example of TotalQuality Management. First she is looking for the variables. Next she is drawing links ( Same / Opposite) After labeling the loops ( Balance or Reïnforce ), the story telling begins.
In ‘our’ model it will look like this:
As you can see, in this model you can ‘play’ the story. Try it yourself.