
Towards the Geo-enabled Model Web 187
WS-BPEL, however, is a description language for defi ning a concrete set
of tasks associated with web services in conjunction with data dependences
among such tasks. WS-BPEL workfl ow descriptions (e.g., Fig. 4), which
point to particular web services used within a workfl ow and specify lots of
details such as input and output data sets (mid-right Fig. 7), are executed
by WS-BPEL-complaint workfl ow engines (bottom-right Fig. 7). Finally,
XPDL acts as the glue standard capable of transforming BPMN diagrams
into executable WS-BPEL descriptions together.
On the other hand, WSDL and WPS specifi cations are widely ...