1. Machine learning was used to create a decision tree model to diagnose problems in telecommunications networks, achieving 99% accuracy with only 10,000 examples. 2. The model was simplified for comprehensibility, becoming probabilistic and covering 50% of cases with general rules and 50% with specific small disjuncts. 3. Lessons from the success include the importance of model comprehensibility, handling small datasets, addressing systematic errors, and considering future extensions when applying machine learning solutions.