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Web Service Composition Plans in OWL-S
Eva Ziaka, Dimitris Vrakas, and Nick Bassiliades
Department of Informatics, Aristotle University of Thessaloniki, Thessaloniki, Greece
{evziaka,dvrakas,nbassili}@csd.auth.gr
Abstract.
One of the main visions of Semantic Web has been the ability of
software agents to compose atomic web services in order to facilitate the auto-
mation of complex tasks. One of the approaches used in the past in order to
automatically construct composite web services has been AI planning. The most
important advantage of this approach is its dynamic character that reduces the
interference of the user. Although there have been various attempts to utilize
planning algorithms and systems in the composition process, there has been lit-
tle work in the field of converting web service composition plans in OWL-S.
This paper studies the use of two well established standards in expressing plans
and composite web services, namely the Planning Domain Definition Language
(PDDL) and the Ontology Web Language for Services (OWL-S) and suggests a
method for translating the produced PDDL plans of any planning system to
OWL-S descriptions of the final composite web services. The result is a totally
new web service that can later be discovered and invoked or even take part in a
new composition.
Keywords:
Web services composition, AI planning, Semantic web services,
OWL-S, PDDL.
1
Introduction
Nowadays, many different systems all over the globe can communicate with each
other through the Internet. The need for supporting interoperability of web applica-
tions so that they can be used by all platforms, no matter their implementation, has led
to web services technology and a new, web-service-oriented way of programming.
This new technology is based on open protocols, such as the XML and the well
known HTTP transfer protocol.
There is often the need to execute more complex tasks that simple web services do
not have the potential to complete on their own. In such cases, simple web services
must cooperate so as to combine their functionalities to create a new complex web
service that will hold the desirable functionality. Semantic information about all the
available atomic web services is very important for their cooperation in web services
composition field, so as to be able to understand the meaning of their inputs and out-
puts and to match them to achieve cooperation.
During the past decade a large number of approaches for composing web services
have been proposed, some fully automated, other partially automated, whereas a lot of
them are even completely manual. A promising way that aims at fully automated web
