Any case studies using Bayesian Networks for system design trades?
As I can see you're searching for a case study. Learning from data is useful because you can learn both the conditional probability distributions (CPDs) and the structure of the network. The best resource I've read is a freely-available Microsoft tech report. 

Have a look at the paper, maybe it can help you upto some extend. I'll suggest you to start with Chapter 7 of it.

Hope it helps. Cheers!