<<With all the promise of SOA, the lack of a common basis for
understanding between consumers and providers is a major roadblock to
realizing value and achieving meaningful reuse. Picture a meeting of
the UN General Assembly without the simultaneous translation that the
delegates receive to ensure proper understanding. The points the
speaker makes would be lost on the intended audience. In fact, the
listeners wouldn't know whether they care about the content or not.

With all the heterogeneity present in most large IT shops, the
communications between systems are like a Tower of Babel without the
ability to recognize common themes. Every packaged application,
home-grown solution and software service has it's own "language"
consisting of vocabulary and grammar along with "cultural" or
context-specific understanding.

The canonical business model

The answer is a canonical business model, defined as an information
model that represents the inherent business concepts without regard to
either individual use or hardware or software implementation.

The common model serves as a universal translator, similar in function
to those employed by earth dwellers and aliens in various science
fiction works to understand each other, facilitating understanding
between the various system semantics.

Understanding is a precursor to action. Once insight has been
achieved, many things become possible – 1) better reuse of services,
2) reuse of published events by multiple automated business process
subscribers and 3) correlation of events and messages across
information streams.

Better reuse of services

Services in an SOA implementation are often described as having
location independence and implementation encapsulation. Oddly enough,
the definition, inputs and outputs are all too often closely tied to
the original underlying implementation. The impact of that is that the
service may not be reused as much as it could be, as the description
may appear too "foreign" to be useful. If the service interface is
defined in terms of a common business language, there is a much better
chance of leverage.

Reuse of published events by multiple subscribers

Business events represent important activities within the enterprise.
To avoid the trap of a point-to-point event-driven architecture, the
events and accompanying information must be understood by all
potential subscribers. Orchestrated business processes become more
flexible and dynamic when the process steps are acting on common objects.

Correlation of events and messages across information streams

In order to see the big picture and accurately understand the state of
the business in real-time, the events and information flows available
across domains must be in the same "language" in order to derive
intelligence from the composite information. Otherwise, it is like
doing arithmetic with fractions without first identifying a common
denominator. Patterns of events and information representing threats
and opportunities can be recognized when the common basis can be assumed.

Creating the business model

A couple of options are available. In some industries, there are
well-established information models that are widely accepted and used.
In those cases, it is often easiest to adopt those models. While often
cumbersome and sometimes overly complex, the benefit is that they can
be leveraged immediately. These industry-standard models are very
useful in business-to-business interactions.

The other option is to create one for internal use in the enterprise.
This can be done incrementally. There is no need to conduct a massive
enterprise modeling project, which is usually impossible to fund, as
long as sound modeling techniques, such as UML domain modeling and
extensible technologies like XML Schema, are used. Architects should
use existing information stores and models to derive key business
domain objects and attributes in order to rapidly create the first
iteration. In the modeling process, it is important to first identify
the core common business objects that are referenced in many business
activities. Specific business process information can then be layered
on by combined those common objects and introducing context-specific
attributes.

Using the model

Heterogeneity is a fact of life in IT today. Therefore, there will
probably never be a common model implemented within all of the systems
that participate in the various business processes. To achieve the
greatest value from the flow of information and events in the
enterprise nervous system, leverage integration technology to
semantically translate the data to and from the canonical business
model as close to the end points as possible. This approach creates a
comprehensive information ecosystem where all participants are on the
same page.

The bottom line is that the full potential of SOA, EDA and CEP
(complex event processing) cannot be realized without a common
business model. The flow of enterprise information delivers real value
when it can be understood and utilized in many contexts. Services will
have a better potential for reuse. All interested subscribers can
consume the same published business events, instead of proliferating
point-to-point event-driven integration scenarios. Flexible
orchestrated business processes can be created across domains using
the common model. Threats and opportunities also can be identified by
correlating events and information across domains.>>

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Gervas

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