First bullet: yes, although you can apply labels to states, transitions, messages etc. But they are attributes of that diagram component rather than being useful in and of themselves.
Second bullet: yes, although there are some tools that can help you iron out some of the issues (like warning you that you've got a use case that isn't covered by any of your state transitions, or a message sequence that can never get triggered).
There is also a "real time extension" for UML that claims to allow you to add clocks and timers and whatnot to your diagrams, and I bet that would also then allow you to simulate stuff happening (again, with the right tools). However, I have never met anybody who had a good word to say about that, other than the people who sell the tools :-)
I suspect some UML proponents would make far greater claims for it than I am making here - my knowledge is based on a years-ago training course which I have used very infrequently since.
no subject
Second bullet: yes, although there are some tools that can help you iron out some of the issues (like warning you that you've got a use case that isn't covered by any of your state transitions, or a message sequence that can never get triggered).
There is also a "real time extension" for UML that claims to allow you to add clocks and timers and whatnot to your diagrams, and I bet that would also then allow you to simulate stuff happening (again, with the right tools). However, I have never met anybody who had a good word to say about that, other than the people who sell the tools :-)
I suspect some UML proponents would make far greater claims for it than I am making here - my knowledge is based on a years-ago training course which I have used very infrequently since.