Semantic Web Technologies for

Service Composition

Dragan Gašević

Athabasca University

Email: dgasevic@acm.org

(How) Are

semantic technologies

related to

service composition?

Topics to discuss about

� Semantic Web and Ontologies

� Semantic Web Services

� Development of Service Compositions

� Conclusion

Part I

Ontologies and MDE

- Basics -

Semantic Web

To create a universal medium for the exchange of data.

… to smoothly interconnect

personal information management,

enterprise application integration and

the global sharing of

commercial, scientific and cultural data.

Semantic Web Activity Statementhttp://www.w3.org/2001/sw/Activity

< musician: Musician rdf:ID="urn:rdf:969914d5ca929194ea18787de32c665a-1"> … <musician:name>Eric Clapton</musician:name> <musician:records rdf:resource = "http://www.guitar.org/legendaryrecordings/EC#urn:rdf:958804d5ca918084ea17676de21c887a-0"/> … </musician:Musician>

Musician

Album

Event

plays

plays at

attends

records

Admirer

Instrument

musician:records

rdf:type rdf:type

<album: Album rdf:ID="urn:rdf:958804d5ca918084ea17676de21c887a-0"> … <album:title>Unplugged</album:title> <album:year>1992</album:year> … </album:Album>

RDF

What is an ontology?

� Important definition (Hendler, 2001)

� a set of knowledge terms, including

� vocabulary

� semantic interconnections

� some simple rules of inference and

logic for some particular topic

Semantic Web

� Ontologies: Interconnecting applications

� Shared domain conceptualizations

Ontology languages

enable reasoning!Not ontologies themselves.

� Logic-based foundation and reasoning

� No agreement about reasoning entailment

Part II

Semantic Web Services

Semantic Web Services

Syntax Syntax

Semantic WebRDF(S), OWL, WSML

Web Services

UDDI, WSDL, SOAP

WebHTML, HTTP

Semantic

Web Services

Computation

Content

� Envisioned evolution of the Web

Automation of service discovery,

composition, invocation, and

monitoring

http://www.wsmo.org/TR/d17/v0.2/

Semantic Web Services

� SWS descriptions languages

� Semantic Annotations for WSDL

and XML Schema (SAWSDL)

� Web Service Semantics (WSDL-S)

� W3C Submissions

� Ontology Web Language for Services (OWL-S)

� Web Service Modeling Ontology (WSMO)

� Semantic Web Service Ontology (SWSO)

Recommendation

SAWSDL : An extension of WSDL

<Operation>

<Output1>

Web service 1

<Input1>

<Operation>

<Output2>

Web service 2

<Input2>

Composition

SAWSDL

<Operation>

<Input1>

<Output1>

Service Template

Operation:buyTicket

Input1:

TravelDetails

Output1:

Confirmation

Annotations

Publish

Search

Semantic UDDIOperation:cancel Ticket

Input1:TravelDetails

Output1:Confirmation

http://lsdis.cs.uga.edu/projects/meteor-s/wsdl-s/WSDL-S-W3C-ppt.ppt

A Conceptual

Model for SWS

A Formal Language for WSMO

A Rule-based Language for SWS

Execution Environment

for WSMO

Web Service Modeling Ontology

http://www.wsmo.org/TR/d17/v0.2/

Current State

� Automation of service

� Discovery

� WSMO-MX, OWLS-MX, SAWSDL-MX – DFKI

� iMatcher – based on iSPARQL

� Composition

� IRS, WSMO Studio

� Invocation

� Monitoring

How do we develop

compositions?

Part III

Service Compositions in

Development Processes

End-user development: AMICOhttp://amico.sourceforge.net/

End-user Development: AMICO

Sequence

Sequence f

Parallel Split

Exclusive choice

f

Simple merge

http://amico.sourceforge.net/

End-user development

Sequence

Sequence f

Parallel Split

Exclusive choice

f

Simple merge

Google maps (with AJAX HTTP connection to AMICO)

http://amico.sourceforge.net/

Not quite Semantic Web!

� But, some very useful lessons learned

� No discovery – variable names

� Ontologies and discovery engines

� Mediation is still a problem

Compositions are

part of end-user apps

� User interaction and user tasks are involved

Linked Data

http://linkeddata.org/static/images/lod-datasets_2009-03-05-scaled.png

Linked Data

SPARLQ end points are

already services

They enable semantic-rich data mash-ups

http://linkeddata.org/static/images/lod-datasets_2009-03-05-scaled.png

Potluck

David F. Huynh, Robert C. Miller, David R. Karger: Potluck: Data mash-up tool for casual users. J. Web Sem. 6(4): 274-282 (2008)

From [Huynh et al, 2008]

Potluck

From [Huynh et al, 2008]

David F. Huynh, Robert C. Miller, David R. Karger: Potluck: Data mash-up tool for casual users. J. Web Sem. 6(4): 274-282 (2008)

Composing Services: WebML

� Start from business processes (in BPMN)

Marco Brambilla, Stefano Ceri, Irene Celino, Dario Cerizza, Emanuele Della Valle, Federico Michele Facca, Andrea Turati, Christina Tziviskou: Experiences in the Design of Semantic Services Using Web Engineering Methods and Tools. J. Data

Semantics 11: 1-31 (2008)

From [Brambilla et al, 2008]

Composing Services: WebML

� End-users interact with discovery engines

� Mediation another key challenge

Marco Brambilla, Stefano Ceri, Irene Celino, Dario Cerizza, Emanuele Della Valle, Federico Michele Facca, Andrea Turati,

Christina Tziviskou: Experiences in the Design of Semantic Services Using Web Engineering Methods and Tools. J. Data

Semantics 11: 1-31 (2008)

From [Brambilla et al, 2008]

Software

Language Engineering

� Language design and transformations

Context-awareness

� Challenges

� User modeling – preferences, goals, etc.

� Learning from experience of other users

Families of Service Compositions

� Domain engineering

� Feature modeling

� Annotation of features

� Services discovery

Families of Service Compositions

� Application Engineering

� Description logic-based staged configuration

� User functional and non-functional requirements

� Combining with soft-requirements – fuzzy DL

� Transforming configuration into WSMO

� Run-time adaptation

Semantic techs can be

useful for automation� But, better understanding is needed

� Applications vs. service compositions

� Service-oriented app. lifecycles

� Adaptivity of service-oriented applications

� Software languages are needed

3rd International Conference on

Software Language Engineering

http://planet-sl.org/sle2010/

Thank you!

Questions?