Global Positioning System Reference
In-Depth Information
XML Process Defi nition Language
The XML Process Definition Language (XPDL)
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is an XML format
standardized by the Workfl ow Management Coalition (WfMC)
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aimed
at interchanging business process defi nitions between different workfl ow
products by defi ning an XML schema for specifying the declarative part
of business workfl ows. The XPDL format is mostly used for exchanging
BPMN diagrams since it has been specifi cally designed to store all aspects of
a BPMN diagram, both the graphic notation and the semantics of a BPMN
process. This distinguishes XPDL from WS-BPEL because the latter focuses
exclusively on the executable aspects of the process. WS-BPEL, in fact,
does not contain elements to represent the graphical aspects of a business
process. Therefore, XPDL has been widely adopted as a common standard
interchange format for BPMN diagrams (Chinosi and Trombetta 2012).
Service-based Modeling
Like a task in scientifi c and business workfl ows, a service is an abstraction
unit that allows modelers to share and encapsulate any piece of functionality.
In service-based modeling, building blocks such as data and processes
are distributed over a network and exposed as services available and
accessible via standard interfaces on the Web (Alonso et al. 2004). In such
a context, service-oriented architectures (SOA) are usually adopted in
the development of collaborative, distributed web applications based on
interoperable services. Friis-Christiensen et al. (2009) defi ne SOA as “an
open and interoperable environments based on reusability and standardized
components and services”. Web services represent autonomous, platform-
independent entities that can be described, published, discovered, and
eventually composed into service compositions to support the development
of rapid, interoperable and massively distributed applications (Papazoglou
et al. 2007; Papazoglou and van den Heuvel 2007).
Web services, as an implementation of a service, can perform functions
that range from answering simple requests to executing sophisticated
analysis and business processes. Indeed, any piece of code deployed in
backend systems and applications can potentially be transformed and
exposed as a web service. One of the required steps to convert a backend
component into a web service is to describe its public service interface so
that potential clients can connect and interact with it.
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http://www.xpdl.org
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http://www.wfmc.org
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