Robust Workflow Systems Flexible Geoprocessing Services Geo-enabled Model Web? - Geographical Information Systems: Trends and Technologies - page 181

In this context, the primary goal of BPMN is to provide a graphical
notation (Fig. 2) that is readily understandable by all business users, from the
business analysts, who create the initial abstract processes, to the technical
developers, who are responsible for implementing these processes, and
fi nally, to the business people, who manage and monitor the life cycle of
these processes. Thus, BPMN creates a standardized bridge for the gap
between the business process design and process implementation (Chinosi
and Trombetta 2012).

Participants

Activities

Event
Subprocess

Call Activity

Task Subprocess Transaction

Data Artifacts

Gateways

Group

Data
Object

Text
Annotation

Data
Store

Inclusive Parallel Event

Exclusive

Fig. 2. Examples of BPMN notation and symbols (Source: http://www.camunda.org).

Web Services—Business Process Execution Language

Under the Organization for the Advancement of Structured Information
Standards (OASIS), 12 WS-BPEL (Jordan and Evdemon 2007) specifi cation
has turned into de facto business process description language for which a
process is defi ned as a workfl ow of web services. WS-BPEL is a description
language composed of variables and operations. These operations have a
strong support to handle XML messages (e.g., SOAP 13 envelopes, i.e., an
XML communication protocol specifi cation under the World Wide Web
Consortium (W3C)) 14 and are able to call various remote web services,
synchronize results, transform them to be packaged as inputs for subsequent
web services in the workfl ow, and store intermediate results in variables.
Figures 3 and 4 illustrate the same toy example of WS-BPEL. Figure
3 shows a graphical representation of a WS-BPEL process composed of
one single web service. Figure 4 lists the XML description of the WS-BPEL
process in Fig. 3. In this simple business workfl ow, only a sequence (line 23)
activity encompasses a couple of receive (line 24) and reply (line 27) activities
to coordinate the fl ow of messages with the web service.

12 http://www.oasis-open.org/
13 http://www.w3.org/TR/soap
14 http://www.w3.org