Grid Services Orchestration with OMII-BPEL - Grid Computing: Infrastructure, Service, and Applications - page 197

8.8
Surrounding the primitive Web service standards like WSDL and SOAP is
an ever-evolving family of Web service standard extensions (WS-*), which
represent the collective thoughts of dei ning and improving the Web service
framework. For example, standards like WS-Addressing, WS-Notii cation,
WS-Policy, WS-Security, and others are considered as benei cial comple-
ments to the primitive Web services framework in their own target areas of
concerns. In a layered environment that will continue to expand and evolve
like this, BPEL will consistently work with Web services through its direct
dependencies on WSDL and SOAP standards orthogonally to the WS-*
extensions. Eventually, it will still be the application data peeled off the SOAP
messages that BPEL is really concerned about.

Web Service Extensions

8.9
BPEL in itself is only a specii cation that does not come with any con-
crete implementations. Being an open standard, it instead encourages
vendor-diverse solutions. OMII-BPEL has bundled up some best-of-
breed open-source software to deliver a fully integrated BPEL environ-
ment that includes a client-side process editor, which eases the effort of
BPEL generation, the BPEL Designer, and a server-side BPEL engine,
which ensures reliable process hosting and enactment, the ActiveBPEL.
The tailor-made environment developed under the OMII middleware
infrastructure is released with other OMII-managed services and tools
on a regular basis.

OMII-BPEL and BPEL Environment

8.10
The BPEL specii cation is a nearly 300-page-long document, including
some 40 pages of XSD schema and another 12 pages of static analysis
rules. All must be applied to validate process documentation. For proper
modeling, the level of complexity is well beyond any existing text edi-
tors or XML editors. It is tedious and error-prone even for experienced
users if no further assistance is available. The provision of GUI editors
that support visual representation of the process model is surely more
than simply having an interactive user interface, nice self-explaining
icons, or an easy drag-and-drop style of composition. Most importantly,

Process Modeling and BPEL Designer