In my experience, the broad concepts of UML are applicable and used in real-world engineering/design. By "broad concepts" I mean something like "draw boxes for

In my experience, the broad concepts of UML are applicable and used in real-world engineering/design. By "broad concepts" I mean something like "draw boxes for classes/objects with arrows pointing to related other objects". Thinking about systems as state machines, sequences, entity relationships, etc is useful. But the rigid details of specific lines styles, arrow types, etc are very rarely used.