An Action is something that is actually done/executed by a actor in some context (i.e. in a specific place, at a specific time). During the time interval in which the action is executed, the actor may still execute other actions in other execution-contexts (multi-tasking). An action is executed on behalf of a specific party, which means that the primary guidance for executing the action, e.g. how to execute it, boundary conditions within which the execution must take place, etc., comes from a policy that this party has established for actions of that kind. The actor is assumed to have appropriate access to that policy.
The Parties, Actors and Actions pattern provides an overview of how this concept fits in with related concepts.
The ability to distinguish between (non)actions allows one to determine which (kinds of) actors are capable of executing actions (e.g. by establishing that they have the competences required by the party), and as a consequence may be permitted and/or required to execute them. Also, this ability enables parties to determine the execution-policy, i.e. the set of rules, working-instructions, preferences and other guidance that actors should obey or comply with when exeucting an action on its behalf.
An Action is something that is done by an actor, can be considered a single operation, and is performed in a specific context, for or on behalf of a specific party, i.e. in accordance with the policy rules that this party has established for such actions.
- filling in a form and submitting it.
- cleaning a car.