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Service Oriented Architecture
The discussion on this page is
based on the Service Oriented Architecture book and articles by
Thomas Erl. [1] It is easy to ignore service-oriented business
modeling and simply focus on service-orientation as it applies to
technology and technical architecture. That, however, is missing the
point of SOA. The architectural model established by SOA and further
defined by the common principles of service-orientation provides the
very real potential to finally unite the business and automation
domains of an enterprise. [2].
Service-orientation allows a
business to structure automated business logic that can
significantly improve the flexibility and agility with which that
logic can be re-modeled in response to change. Such an environment
is responsive in that changes to business requirements or business
processes can be efficiently accommodated through the re-composition
of these services.
SOA is based on principles of
service reuse, loose coupling and service discoverability.
Business service modeling marries the principles of
service-orientation with an organization's business models. The
process of modeling business services forces the organization to
view and reinterpret business knowledge in a service-oriented
manner. The resulting perspective can clearly express how services
relate to and embody the fulfillment of business requirements.
There are three primary business
service models [3]
- Entity-centric business
service
- Task-centric business service
- Process service
Entity-centric business
service
The entity-centric business
service model requires to group functionality according to a context
associated with a predefined business entity or information set.
Common business entities in academic institutions include student
admission, course registration, financial aid processing, course
grade report, graduation, refund calculation upon withdrawal, and
various reporting requirements, including, SSCR and so on.
AcademicEdge student system uses an entity-centric service model, in
which, some of the above entities have been implemented and enabled as a
web services.
The emergence of this service model is one of the
most important developments in the evolution of service-oriented
computing so far. It introduces new design, deployment and
maintenance considerations that increase the complexity of an
enterprise’s service architecture, but also provides the potential
of realizing some of the significant strategic benefits associated
with SOA.
Business Process Management
The
concept behind BPM is to help organizations automate and optimize
their business processes and performance. BPM products provide
process modeling tools and key performance indicators to monitor and
measure against operational targets. BPM encompasses both system and
human workflows. [4]
According
to Stephanie Wilkinson, manager of WebSphere product marketing for
IBM, "BPM is one of the main entry points for the business side of
SOA. SOA is about building reusable services. BPM is focused on
business processes and management and how you do modeling and
monitoring. You want to do all that on top of an SOA so you have a
flexible architecture. They will be tightly linked."
According
to Ron Schmelzer, a senior analyst at ZapThink LLC, over time BPM
and SOA will become more complementary. "BPM in general is the idea
that we can model a business in terms of its processes and then
represent them in a way that computers can understand and process.
SOA has as its fundamental core the idea that business processes
should be represented as services and then exposed as services so
that different applications can consume and compose them in a
loosely coupled manner," he said. "This means that as companies move
to adopt SOA, they will necessarily implement BPM solutions as
service-oriented versions, representing processes as services and
BPM tools simply as service-oriented composition applications."
While BPM
is independent of the underlying architecture, "the combination of
BPM and SOA makes a killer platform," Mohindroo said. "It's easier
to shorten the gap between the definition of a business process and
execution with SOA. It's easier to pull and access applications in
the back end and tie them to business processes. That is the direction
we're moving with Oracle Fusion." [5]
Oracle's
BPEL Process Manager is part of the Fusion middleware suite. In
addition, Mohindroo said Oracle Fusion applications, which will
begin rolling out in 2008, will embed the BPEL Process Manager.
While BPM
may have started with workflow, SOA is helping to make end-to-end
BPM possible, said Pierre Fricke, director of product management for
JBoss, now a division of Red Hat Inc. "There are hundreds of vendors
that solve BPM from a vertical angle, many started in the workflow
arena," he said, "but all are quite limited and disjointed. There
were no real standards before we got to an SOA fabric. Now we've got
BPEL. You couldn't do end-to-end BPM before. You could [only] do
pieces because the IT environment may have been incompatible. In the
new world BPM can cross these silos lot easier than before."
JBoss
offers the jBPM system as part of its open source JBoss Enterprise
Middleware Suite (JEMS). The 3.1 version added multiprocess language
support and integration with JBoss Seam, the company's framework for
building Java applications. "With jBPM you may have BPEL
orchestration, but you also need Java process automation because not
all services are Web services. Some may be Java endpoints," he
said.
"A lot of
BPM suites have proprietary technology built in, but most BPM
products are migrating toward open standards and most of the ESBs
have a BPEL [Business Process Execution Language] engine," said Anne
Thomas Manes, vice president and research director at Burton Group.
"BPM has human workflow plus system workflow; BPEL is basically
system-to-system workflow, but that's starting to merge." [6]
Business
Manager from Savvion Inc. in Santa Clara, Calif., is an example. An
organization can publish its processes as services and subscribe to
other services, which in turn can become part of their processes.
Savvion's BPM Studio can publish that process in a UDDI directory.
References:
[1] Erl, Thomas, Service-Oriented Architecture:
Concepts, Technology, and Design, Prentice Hall/Pearson PTR,
ISBN: 0131858580, 2006 <www.soabooks.com.>
[2] Erl,
Thomas, “The benefits of business services”, 22 Feb 2006, <http://searchwebservices.techtarget.com/tip/1,289483,sid26_gci1168438,00.html?track=NL-588&ad=544028>
[3] Erl,
Thomas, “Business service models and the entity-centric business
service”, 22 Mar 2006, <http://searchwebservices.techtarget.com/tip/1,289483,sid26_gci1174702,00.html?track=NL-588&ad=547678>
[4] Frye,
Colleen, “Special Report: BPM inside the belly of the SOA whale”, 15
Jun 2006, <http://searchwebservices.techtarget.com/originalContent/0,289142,sid26_gci1193780,00.html>
[5] Frye,
Colleen, “Special Report: BPM inside the belly of the SOA whale,
part 2”, 22 Jun 2006, <http://searchwebservices.techtarget.com/originalContent/0,289142,sid26_gci1195582,00.html>
[6] Frye,
Colleen, “Special Report: BPM inside the belly of the SOA whale,
part 3”, 29 Jun 2006, <http://searchwebservices.techtarget.com/originalContent/0,289142,sid26_gci1196723,00.html> |
