In a sufficiently complex system there are some places where some UML is considered useful.
The useful diagrams for a system, vary by applicability.
But the most widely used ones are:
- Class Diagrams
- State Diagrams
- Activity Diagrams
- Sequence Diagrams
There are many enterprises who swear by them and many who outright reject them as an utter waste of time and effort.
It's best not to go overboard and think what's best for the project you are on and pick the stuff that is applicable and makes sense.
