3.1.2 Action and
Joint Action
Entities act in order to achieve their goals. In this model, we look at the most basic form of action – an
action performed by a single actor – and the case of joint action as required
by SOA participants to realize desired real world effects.
3.1.2.1 Action and
Actors
Figure 6
depicts a model of action showing the relationships between action, goals and
effects of action. Here, we focus on the actions of individual entities. However, we should remark that for the
most part within a SOA ecosystem, the actions we are most interested in are
actions involving multiple participants – we address this further in Section 3.1.2.2.
Figure 6
Actions, Real World Effect and Events
The most important concept in any model of actions and
effects is that of action itself:
Action
An action is the
application of intent to achieve a
real world effect (within the SOA
ecosystem).
This concept is simultaneously one of the fulcrums of the
Service Oriented Architecture and a touch point for many other aspects of the architecture:
such as policies, service descriptions, management, security and so on.
The aspect of action
that distinguishes it from mere force or accident is that someone or something
intended the action to occur.
Goal
A goal is a
measurable state of the ecosystem that an actor is seeking to establish.
Goals are conditions that people, and more generally actors,
are seeking to satisfy. A key aspect of goals is measurability: it should be possible
to know if a goal has been satisfied.
Intent
Intent is the
commitment of an actor to achieve a goal.
An actor’s intent
in performing an action is to
further one or more of the actor’s goals.
Although action
causes real world effects and intent
can be seen in terms of desired real world effects, it is possible that the
real world effect caused by an action may not be the one(s) intended. In
extreme situations, the actual effects will include unintended consequences
that fall outside of, and may run counter to, the intent of the actor. A key aspect of goals is measurability:
it should be possible to know if a goal has been satisfied, and this is most
often accomplished by examining whether the desired real world effects
occurred.
In some situations it may be difficult to determine an actor’s actual intent. This is particularly true for social actions such as those performed
within a SOA-based system.
However, in most cases, entities in a SOA ecosystem make
an assumption of implied intent. I.e.,
if an actor performs an action, it is assumed that the actor also intended to perform the action – it was not an accident, or the
action of another actor.
[KL1]Much
of the infrastructure of interaction is there to eliminate the potential for accidental
or malicious actions.[KL2]
Effect
An effect is
a measurable change in the state of the ecosystem.
[KL3]Note
the normal intent of applying an action is to cause an effect that reflects the actor’s goals.
However, there is often the possibility that the actual effects will include unintended
consequences that fall outside of, and may run counter to, the intent of the actor.
Changes in the ecosystem may be reported by means of events:
Event
An event is the
report of an effect of which at
least one participant has an interest in being aware.
An event is a
corollary to action, where actions
result in changes to the state of ecosystem (primarily changes to the states
of individual participants)[KL4];,
and these changes may be manifested as events
of which participants in the ecosystem have an awareness.
Note that, while performing an action may be an event in
which other participants have an interest, an event that reports an action
is not the same as the action
itself.
[KL1]Disagree! Part of establishing trust is deciding whether an actor is reliable and not prone to error. It cannot be assumed ahead of time, any more (or less) than one can make this assumption in typical experiences.
[KL3]should state things in terms of the RM concept of RWE or need to explicitly relate effect to RWE.
[KL4]It would be difficult to argue the states changed are “primarily” those of participants and not the states of things, e.g. data objects.