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Wednesday, April 2, 2008

Effective, Agile, and Connective

Composite applications built from predefined enterprise services form
the core of enterprise service-oriented architecture (enterprise SOA).
Ultimately the goal of enterprise SOA is composition of any service
implemented on any technology by any business partner anywhere in the
world. Open, standards-based technology is a key factor in achieving
this level of interoperability -- similar to plugging a telephone into
the wall. Some of the standards needed relate to the technology used
to implement enterprise SOA, while others define business semantics
and the languages used to describe them... In enterprise SOA, business
semantics consist of definitions of enterprise services and business
processes. These definitions must be described in a manner that allows
the technology layer of the architecture to use them to good effect.
There are three types of definition languages, for processes, service
interfaces, and message content. Process definition languages define
the sequence and conditions in which the steps in a business process
occur. With machine-readable definitions, a business process platform
can ensure that the steps are followed correctly. The need for this
ability is related to the way businesses work -- reacting to an event
with an activity. An event can be almost anything -- contact with a
customer or supplier or reception of an order or an invoice. Enterprises
need a way to describe -- clearly and unambiguously -- how the events
that occur relate to activities in the business. The most important
standard for defining processes is Business Process Modeling Notation
(BPMN). It provides a business-oriented, graphical way of identifying
events and describing activities in easy-to-understand diagrams.
Process definition is a critically important area for enterprise SOA,
and BPMN delivers good business value... Message definition languages
are used to define the structure and content of the data that an
enterprise service sends, receives, or consumes. For example, they
define that the same field always has the same name in all messages.
The languages also describe how to combine fields into larger structures,
how to specialize or extend fields and messages to meet specific needs,
and how to represent the message as an XML schema, for example. [A]
leading standard language for message definition is the UN/CEFACT Core
Components Technical Specification (CCTS). UN/CEFACT is the organization
that also developed the international version of EDI. CCTS provides a
rigorous methodology for defining data unambiguously and includes
rules about how to convert language-neutral definitions into XML. Clear,
consistent definitions of the messages used by enterprise services
deliver business value.

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