Information Technology Reference
In-Depth Information
object. It acknowledges that it is not feasible to fully specify the structure of an object
upon its creation because of inputs needed from multiple stakeholders, and because of
the artificial nature of the object itself. Refinement can occur via decomposition or
elaboration. For example, one can refine the understanding of an automobile engine in
two ways: adding facts about engine features, e.g. the displacement or horsepower
(refinement); or exposing sub-components, e.g. block, head, and pistons (decomposi-
tion). Elaboration may require addition of Invented Attributes enhancing commitment
from stakeholders; decomposition may result in addition of Conceptual Objects or
Events providing a way to scale down commitment.
4.4 Specialization
Specialization (S) is the construction of variations on the basis of Concrete or Con-
ceptual objects. It corresponds to the idea of creating sub-classes. It is qualitatively
different from Elaboration in that Specialization involves spawning new objects that
are still within the boundaries specified by the source object. Consider, for example, a
global producer of manufactured products with customers in different countries. Each
may have different trade rules regarding import tariffs. Here, Specialization may be
applied to the object Country to distinguish between non-tariff countries and tariff
countries by identifying and including different attributes that are part of each
new object. During the EA life cycle, Specialization can help different stakeholders
negotiate their spheres of responsibility.
4.5 Derivation
Derivation (D) refers to the changing of the form of one or more elements without
changing its content. It is a critical operation during the EA life cycle because it goes
beyond Specialization or Refinement. Unlike these two, Derivation allows manipula-
tion of specific attributes, including attributes from multiple objects without the need
to generate a new Object or a permanent elaboration of an Object. It allows stake-
holders to combine attributes from a number of related Objects in response to their
information needs. As an example, consider the derivation of elements necessary for
an ISO 19439 (ISO 2006) model description from a Zachman Framework description.
Derivation may also involve computation of aggregates based on values of attributes
from component objects or attributes from other related objects.
4.6 Linking
Linking (L) is the idea that elements - Concrete and Conceptual Objects, Concrete
and Conceptual Events - may be connected via arbitrary associations. The need for
links arises because EA models can contain representations at different levels of ab-
straction. Consider, for example, the creation of a link within a meta-level or across
meta-levels or between components in a part hierarchy. The transformations resulting
from links are often implicit or unstated. The link between a process and the role that
is going to be responsible for completion of that process transforms the process into a
managed activity. The linking may also be the result of a business rule applied during
a refinement in the architecture model.
