DAMLS: Bringing Services to the Semantic Web

1
DAML-SBringing Services tothe Semantic Web

• David Martin
• SRI International
• http//www.daml.org/services/

2
DAML-S Web Services Coalition

• BBN Mark Burstein
• CMU Massimo Paolucci, Katia Sycara
• ICSI Srini Narayanan
• Nokia Ora Lassila
• Stanford KSL Sheila McIlraith
• SRI David Martin
• Southampton Terry Payne
• USC-ISI Jerry Hobbs
• Yale Drew McDermott
• Contributed to these slides

3
Outline

• Motivation Goals
• DAML-S technical overview
• Profile, Process Grounding ontologies
• Achievements to date
• Releases, tools applications
• Challenges
• Next Steps

4
Convergence on Services

• Commercial vendors, media, forecasters, etc.
• Intranets, not just internets
• W3C Web services efforts
• Semantic Web community
• DAML-S WSMF other EU efforts
• ISWC 10 services-related papers, 7 posters
• Grid computing (OGSA)
• Ubiquitous computing (devices)
• Mobile access to services
• ? A remarkable opportunity
• Bringing behavioral intelligence to the Web

5
What is DAML?

• A DARPA program
• An input to the W3C Semantic Web activity
• Draft for the Web Ontology working group
• A markup language
• www.daml.org

6
Characteristics of DAML

• Based on XML RDF(S)
• Beyond RDF properties of properties, equivalence
  and disjointness of classes, more constraints,
  etc. Feature comparison https//www.daml.org/lan
  guage/features.html
• Layered approach
• XML RDF(S) DAMLOIL (DAML-L) DAML-S
• Semantics for Web resources from Knowledge
  Representation concepts
• DAMLOIL can be regarded as a description logic
• Ontologies
• Logical rules inference
• DAML-S Extension to Services

7
What is DAML-S?

• DARPA Agent Markup Language for Services
• A DAMLOIL ontology/language for (formally)
  describing properties and capabilities of Web
  services
• An approach that draws on many sources
• Description logic
• AI planning
• Workflow
• Formal process modeling
• Agents
• Web services
• http//www.daml.org/services/

8
Layered Approach to Language Development

• DAML-S a major application of DAMLOIL
• Future versions will build upon emerging layers
  (e.g. DAML-Rules)

DAML-S (Services)
DAML-??? (Rules, FOL?)
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DAML-S Objectives

• Automation of service use by software agents
• Ideal full-fledged use of services never before
  encountered
• discovery, selection, composition, invocation,
  monitoring
• Useful in the real world
• Compatible with industry standards
• Incremental exploitation
• Enable reasoning/planning about services
• e.g., On-the-fly composition
• Integrated use with information resources
• Ease of use powerful tools

10
Automation Enabled by DAML-S

• Web service discovery
• Find me a shipping service that transports goods
  to Dubai.
• Web service invocation
• Buy me 500 lbs. powdered milk from
  www.acmemoo.com
• Web service selection composition
• Arrange food for 500 people for 2 weeks in
  Dubai.
• Web service execution monitoring
• Has the powdered milk been ordered and paid for
  yet?

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Upper Ontology of Services
Ontology images compliments of Terry Payne,
University of Southampton
12
Service Profile What does it do?

• High-level characterization/summary of a service
• Used for
• Populating service registries
• A service can have many profiles
• Automated service discovery
• Service selection (matchmaking)
• One can derive
• Service advertisements
• Service requests

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Service Profile
Non Functional Properties
Functionality Description
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Service Profile Capability Description

• Specification of what the service provides
• High-level functional representation in terms of
• preconditions
• inputs
• (conditional) outputs
• (conditional) effects

• Summarizes the top-level Process (described by
  Service Model)

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Service Profile Functional Attributes

• Provide supporting information about the service,
  including

• geographical scope
• Pizza Delivery only within the Pittsburgh area
• quality descriptions and guarantees
• Stock quotes delivered within 10 secs
• service types, service categories
• Commercial / Problem Solving etc
• service parameters
• Average Response time is currently ...

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Service Profile Styles of use

• Class-hierarchical yellow pages
• Implicit capability characterization
• Arrangement of attributes on class hierarchy
• Can use multiple inheritance
• Process summaries for planning purposes
• More explicit
• Inputs, outputs, preconditions, effects
• Less reliance on formal hierarchical organization
• Summarizes process model specs

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Exploiting Taxonomies of Services
nameproviderroleavgResponseTime?
ServiceProfile
FeeBased
feeBasispaymentMethod
ProductProvidingService
ActionService
Physical_Product
Manufacturing
InfoService
InformationProduct
physicalProductmanufacturerdeliveryRegiondel
iveryProviderdeliveryType
PhysicalProductService
Repair
physicalProduct
Tie in with UDDI, UNSPSC, DL Basis for
matchmakingMultiple profiles multiple taxonomies
transportationModegeographicRegion
Transportation
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Upper Ontology of Services
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Service ModelHow does it work?
Process Model How does it work?

• Process
• Interpretable description of service providers
  behavior
• Tells service user how and when to interact
  (read/write messages)
• Process control
• Ontology of process state supports status
  queries
• (stubbed out at present)
• Used for
• Service invocation, planning/composition,
  interoperation, monitoring
• All processes have
• Inputs, outputs, preconditions and effects
• Function/dataflow metaphor action/process
  metaphor
• Composite processes
• Control flow
• Data flow

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Service Model / Process Model
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Function/Dataflow Metaphor
Input
Output

• customer name
• origin
• destination
• weight
• pickup date
• ...

• confirmation no.
• ...

Acme Book Truck Shipment
Y
truck available valid credit card
?
N

• failure notification

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AI-inspired Action/Process Metaphor
Output

• confirmation no.
• ...

Input

• customer name
• origin
• destination
• pickup date
• ...

• goods at location
• if successful
• credit card debited...

Effect
Y
truck available valid credit card
?
Preconditions
N

• knowledge of
• the input
• ...

• failure notification

Output

Effect
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Composite Process
Output Effects
Input Preconditions
AcmeTruckShpng

• confirmation no.
• ...

• customer name
• location
• car type
• dates
• credit card no.
• ...

www.acmecar.com book car service
?

• failure notification

?

• confirmation no.
• ...

• confirmation no.
• dates
• room type
• credit card no.
• ...

• confirmation no.
• ...

www.acmehotel.com book hotel service
?

• customer name
• flight numbers
• dates
• credit card no.
• ...

www.acmeair.com book flight service
?

• failure notification

• failure notification
• errror information

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Simple and Composite Processes
AcmeTruckShpng
ExpandedAcmeTruckShpng
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Process Model Recent evolution

• Conditional outputs effects
• Parameter bindings
• alues rdfparseType"damlcollection"
  
  theProperty"fullCongoBuyBookISBN"/
  
  theProperty"outInCatalogBookISBN"/
  
  theProperty"congoBuyBookISBN"/
  s
• ? Pushing the limits of DAMLOIL expressiveness

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Upper Ontology of Services
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Service Grounding How to access it

• Implementation-specific
• Message formatting, transport mechanisms,
  protocols, serializations of types
• Service Model Grounding give everything needed
  for using the service
• Examples HTTP forms, SOAP, KQML, CORBA IDL, OAA
  ICL, Java RMI

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DAML-S / WSDL Grounding

• Web Services Description Language
• Authored by IBM, Ariba, Microsoft
• Focus of W3C Web Services Description WG
• Commercial momentum
• Specifies message syntax accepted/generated by
  communication ports
• Bindings to popular message/transport standards
  (SOAP, HTTP, MIME)
• Abstract types extensibility elements
• Complementary with DAML-S

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DAML-S
DL-based Types
Process Model
Inputs / Outputs
Atomic Process
Message
Operation
Binding to SOAP, HTTP, etc.
WSDL
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DAML-S / WSDL Grounding (contd)
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DAML-S / WSDL Grounding (contd)
WSDLDocument


daml-property
inputX
daml-property
outputY
daml-s-process
AtomicProcess
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Review Upper Ontology of Services
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Key
Publication
Profile
Discovery
Simulation

Selection
Process Model
Verification
Composition

Invocation, Interoperation
Grounding

Monitoring, Recovery
Development Deployment Use
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Path of Evolution

• Release 0.5 (May 2001)
• Initial Profile Process ontologies
• Release 0.6 (December 2001)
• Refinements to Profile Process
• Resources ontology
• Two approaches to formal semantics
• Sycara/Ankolekar, McIlraith/Narayanan
• Release 0.7 (October 2002)
• DAML-S/WSDL Grounding
• Profile, Process Model refinements
• More complete examples
• Towards 1.0
• Expressiveness issues process modeling industry
  tie-in

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Related Activities

• Web site mailing lists
• http//www.daml.org/services/
• www-ws_at_w3.org
• Users
• UMCP (Hendler/Parsia), UMBC (Finin), Manchester
  (Goble), CMU (Sadeh), Lockheed-Martin, Ultralog,
  beta-reviewers,
• Tools
• DAML-S publications
• WWW10 SW Workshop (2), SWWS, WWW11, Coordination
  2002, AAMAS, ICSW (4), IEEE Computer, IEEE
  Intel. Systems
• W3C Web services activities
• Designated liaison for WS Arch. WG Katia Sycara
• Experiment
• Use cases

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Tools and Applications
DAML-S is just another DAMLOIL ontology ? All
the tools technologies for DAMLOIL are
relevant Some DAML-S Specific Tools and
Technologies Discovery, Matchmaking, Agent
Brokering CMU, SRI (OAA), Stanford KSL
Automated Web Service Composition Stanford KSL,
BBN/Yale/Kestrel, CMU, MIT,
Nokia, SRI DAML-S Editor Stanford KSL, SRI,
CMU (profiles), Manchester Process Modeling
Tools Reasoning SRI, Stanford KSL Service
Enactment /Simulation SRI, Stanford KSL Formal
Specification of DAML-S Operational/Execution
Semantics CMU, Stanford KSL, SRI
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Challenges

• Finding the 80/20 line
• Profiles relationship with processes
• Process modeling many issues
• Variability of public/private aspects of
  Processes
• Extending to offline (sub)processes
• Generalizing to multiple roles
• Failure, transactions
• Where and how to go beyond DAMLOIL?
• Interface between DL ontology, logical
  expressions, algorithm/workflow representation
• Connecting with Industry
• Showing compelling value
• Not promising too much
• Providing an incremental path

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Next steps / priorities

• Focus on use cases ? architecture
• Joint committee forming
• Move to OWL
• Model information services
• Profile More substantial illustrative taxonomies
• Tie in with existing taxonomies where possible
  (e.g. UNSPSC)
• Process Model
• Evaluate potential tie-in with an existing effort
  (WSFL?)
• Support real-world use
• Describing and using public WSDL services
• Possible collaborations with other SemWeb
  projects
• Demos directed towards Web services community
• Tools
• DAML-S API

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(Some) Related Work

• Related Industrial Initiatives
• UDDI ebXML
• WSDL .Net
• XLANG Biztalk, e-speak, etc
• These XML-based initiatives are largely
  complementary to DAML-S.
• DAML-S aims to build on top of these efforts
  enabling increased expressiveness, semantics, and
  inference enabling automation.
• Related Academic Efforts
• Process Algebras (e.g., Pi Calculus)
• Process Specification Language (Hoare Logic,
  PSL)
• Planning Domain Definition Language (PDDL)
• Business Process Modeling (e.g., BMPL)
• OntoWeb Process Modeling Effort

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Summary

• The service paradigm will be a crucial part of
  the Semantic Web
• DAML-S supports service descriptions that are
  integral with other Semantic Web meta-data
• DAML-S aims to enable automatic discovery,
  selection, invocation, composition, monitoring of
  services
• Initial versions of Profile, Process, and
  Grounding ontologies are available
• Many challenges remain
• Were interested in synergy with related work
• http//www.daml.org/services/

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Acknowledgements

• Slides created by David Martin, Sheila
  McIlraith, Terry Payne
• Ontology images created by Terry Payne, CMU