When to destroy in a sequence diagram

Question

I can't actually find a clear answer for this. In a lot of online design tools (e.g. Web Sequence Diagrams), there is an option to "activate" and "deactivate" a process, whilst there is a separate action to "destroy" the process. When is this used?

If in the diagram I am modelling I am connecting to an online stream, when I am done with it do I deactivate it or destroy it? When I use an application and it is finished, do I deactivate it or destroy it?

Answer 1

In UML a destroy in a sequence diagram means 'a kind of message that represents the request of destroying the lifecycle of target lifeline', i.e. the message recipient object is logical or physical deleted and not available anymore for upcoming interactions. Deactivate would mean the message recipient object would change from an active state to an inactive one, with the possibilty to reactivation in a later state. so the objects is still available in the application space, but could for example moved to an archive over time.

Answer 2

Destroying would make sense if you do show an instantiate step somewhere in your diagram.

• For existing resource like online stream activate/deactivate will make more sense.
• For things like launching a script execution instantiate/destroy will be better.