Information Technology Reference
In-Depth Information
Action compositions can be specified to form processes. A process is
a collection of steps taking place in a prescribed manner and leading to an
objective. A step is an abstraction of an action, used in a process, that leaves
unspecified the objects that participate in that action. Steps are introduced
in the definition because not all the action details need be specified in the
composition. The objective is present because the goal of a process should
always be made explicit in its specification. In ODP, the objective of an
element expresses its practical advantage or intended effect. It is expressed as
preferences about future states.
1.3.4 Grouping Objects Together
ODP distinguishes different ways of organizing sets of objects. In the sim-
plest case, objects can be organized into groups, which are sets of objects
with a particular relationship that characterizes either some structural in-
terdependence between them, or an expected common behaviour. Examples
are the group of all the information objects, or the group of engineering objects
that are related to a given computational object.
Domains are often used in describing these groupings; a domain is a set of
objects related by a characterizing relationship to a controlling object. Every
domain has its associated controlling object, which is not generally itself a
member of the domain. One example of this is a naming domain, in which a
set of names are associated with objects by the controlling object. Another
is a management domain in which a set of printer objects is managed by a
controller.
Objects can also be organized into configurations, which are collections
of objects linked by their interactions at particular interfaces. Examples are
the configuration of objects that together provide a given service, or the con-
figuration of engineering objects that implements a channel.
These concepts can be specialized in specific viewpoints. For example, in
the enterprise language, a community is a configuration of enterprise objects
formed to meet a particular objective, as specified in a given contract . In
our PhoneMob example, one community is the configuration of objects that
together provide the basic repair services to customers. Another community
is the logistics organization formed by a set of objects with the objective of
providing delivery services to users in a secure and timely manner. A third
example is the banking community, which is a configuration of enterprise
objects that together provide a set of banking services (payments, money
transfer and so on) to its customers.
Finally, a federation is a community of domains formed to meet a shared
objective. It models many commercial situations, such as the setting up of
partnerships and joint ventures; examples are the federation of a set of air-
lines that agree to work together to provide transportation services to their
customers by means of code-shared flights, or a federation of banks that share
their ATMs so that customers can use any of them interchangeably. In our
