I totally agree with picking bits and pieces. My favs were the state diagrams. I remember a couple of times when they saved the day. It was a matter of communic

I totally agree with picking bits and pieces. My favs were the state diagrams. I remember a couple of times when they saved the day. It was a matter of communication with the customers, a way to show them that their initial description was light years from a real specification and make them commit with the agreed diagram. Believe it or not, the customers understood it perfectly, after some minutes drawing and deleting lines. There was never a single complaint about that module and only minor bugs, not affecting to the functionality. I hated use cases diagrams, only useful for CYA purposes. The classes diagrams that I've seen in the wild were E/R models translated to UML, but they were the most part of documentation for some projects, so it was better than nothing. The traceability systems from requirements to complete UML diagrams to code were a bunch of good intentions that fortunately never materialized.