An action is part of a transition. It is used to show what the transition must to do ( It may cause events, create or destroy objects and relationships, observe objects and relationships and send or receive messages, etc ). An action is like a procedure and it is always terminates.

Normally, we record an action below a line under the transition's trigger.

There have two kinds of actions: noninterruptible actions and interuptible actions. noninterruptible actions are the actions that when they start running, it can not be interrupted unless the system error happens. Interrptible actions can be interrupted and resumed later.

Compare with actions, we use state or sometimes even entire state net to represent activities or process. See also: state transition

Here is a short quiz so you can test your understanding of Actions.

Go to the OSA Tutorial ORM

Go to Triggers, Conditions, and Events Initial Transition

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Created Thurs Oct. 6 16:28:10 1994 ...
Updated Thurs Nov. 23 13:25:12 1994
by Wei Wei (