David Martin for DAML-S Coalition 12/18/2002 DAML-S: Bringing Services to the Semantic Web David Martin SRI International

David Martin for DAML-S Coalition 12/18/2002

DAML-S:Bringing Services tothe Semantic Web

David Martin

SRI International

http://www.daml.org/services/


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


Outline

Motivation & Goals DAML-S technical overview

Profile, Process & Grounding ontologies

Achievements to dateReleases, tools & applications

ChallengesNext Steps


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


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


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/language/features.html

– Layered approach XML => RDF(S) => DAML+OIL => (DAML-L) => DAML-S

• Semantics for Web resources from Knowledge Representation concepts– DAML+OIL: can be regarded as a description logic

– Ontologies

– Logical rules & inference

• DAML-S: Extension to Services

https://www.daml.org/language/features.html


What is DAML-S?

• DARPA Agent Markup Language for Services • A DAML+OIL 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



Layered Approach to Language Development

DAML-??? (Rules, FOL?)

XML (Extensible Markup Language)

RDF (Resource Description Framework)

RDFS (RDF Schema)

DAML+OIL OWL (Ontology)

DAML-S (Services)

DAML-S: a major application of DAML+OILFuture versions will build upon emerging layers (e.g. DAML-Rules)


DAML-S ObjectivesAutomation 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 standardsIncremental exploitation

Enable reasoning/planning about servicese.g., On-the-fly composition

Integrated use with information resourcesEase of use; powerful tools


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?


Upper Ontology of Services

Ontology images compliments of Terry Payne, University of Southampton


High-level characterization/summary of a serviceUsed for

• Populating service registries• A service can have many profiles

• Automated service discovery• Service selection (matchmaking)

One can derive:• Service advertisements• Service requests

Service Profile: “What does it do?”


Service ProfileNon Functional Non Functional PropertiesProperties

Functionality Functionality DescriptionDescription


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)


Service Profile: Functional Attributes

– geographical scopePizza 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 parametersAverage Response time is currently ...

Provide supporting information about the service, including:


• 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

Service Profile: Styles of use


Exploiting Taxonomies of ServicesServiceProfile

ProductProvidingService

Manufacturing

Transportation

ActionService

InfoService

PhysicalProductService Repair

InformationProduct+

physicalProduct+manufacturer+

deliveryRegion*deliveryProvider*

deliveryType

Physical_Product+

transportationMode+geographicRegion+

physicalProduct+

Tie in with UDDI, UNSPSC, …DL Basis for matchmakingMultiple profiles; multiple taxonomies

nameprovider

role+avgResponseTime?

…

FeeBased feeBasis+paymentMethod+




Service Model“How does it work?”

Process– Interpretable description of service provider’s 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

Process Model: “How does it work?”


Service Model / Process Model


Acme Book

Truck Shipment

Function/Dataflow Metaphor

Input:

• confirmation no.• ...

Output:

• failure notification• …

truck available+

valid credit card

Y

N?

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


AI-inspired Action/Process Metaphor

Input:


Output:


truck available+

valid credit card

Y

N?

Preconditions:

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

• knowledge of the input• ...

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

Effect:

Output:

Effect: <no effect>

Acme Book

Truck Shipment


AcmeTruckShpng

www.acmeair.com

book flight service

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


• failure notification• errror information• …

?

www.acmehotel.com

book hotel service

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



?

www.acmecar.com

book car service

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



?

• • • •

Composite Process

• • • • • • • • • •

• • • •

?

• • • • • • • • • • •

Input &Preconditions

Output &Effects

• • • •

• • • •


Simple and Composite Processes

truck available+

valid credit card

Y

N

Confirm Shipping Region

Get Quote

Get Shipping Dates

Book Truck Shipment

Acme

Truck

Shipping

Service

expands

AcmeTruckShpng ExpandedAcmeTruckShpng


• Conditional outputs & effects

• Parameter bindings<rdf:Description rdf:about="#FullCongoBuy">

<sameValues rdf:parseType="daml:collection"> <ValueOf atClass="#FullCongoBuy“ theProperty="#fullCongoBuyBookISBN"/> <ValueOf atClass="#LocatedBookOutput“ theProperty="outInCatalogBookISBN"/> <ValueOf atClass="#CongoBuyBook“ theProperty="#congoBuyBookISBN"/></sameValues>

Pushing the limits of DAML+OIL expressiveness

Process Model: Recent evolution




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


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


DL-based Types

WSDL

DAML-S

Process Model

Atomic Process

Operation Message

Inputs / Outputs

Binding to SOAP, HTTP, etc.


DAML-S / WSDL Grounding (cont’d)


daml-property

daml-s-process

inputX

daml-propertyoutputY

AtomicProcess

WSDLDocument

<message …> <part …>

<message …> <part …>

<operation …>

<binding …>

DAML-S / WSDL Grounding (cont’d)


Review: Upper Ontology of Services


Pro

cess

Mod

el

Gro

undi

ng

Development … Deployment … Use …

Publication

Simulation

Verification

Discovery

Composition

Key:

Selection

Invocation, Interoperation

Monitoring, Recovery

Pro

file


Path of EvolutionRelease 0.5 (May 2001)

Initial Profile & Process ontologies

Release 0.6 (December 2001)Refinements to Profile & ProcessResources ontology

Two approaches to formal semanticsSycara/Ankolekar, McIlraith/Narayanan

Release 0.7 (October 2002)DAML-S/WSDL GroundingProfile, Process Model refinementsMore complete examples

Towards 1.0Expressiveness issues; process modeling; industry tie-in


Related ActivitiesWeb site & mailing lists

http://www.daml.org/services/[email protected]

UsersUMCP (Hendler/Parsia), UMBC (Finin), Manchester (Goble), CMU (Sadeh), Lockheed-

Martin, Ultralog, beta-reviewers, …

ToolsDAML-S publications

WWW10 SW Workshop (2), SWWS, WWW11, Coordination 2002, AAMAS, ICSW (4), IEEE Computer, IEEE Intel. Systems…

W3C Web services activitiesDesignated liaison for WS Arch. WG; Katia Sycara

ExperimentUse cases


Tools and ApplicationsDAML-S is just another DAML+OIL ontology

All the tools & technologies for DAML+OIL 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


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 DAML+OIL?– Interface between DL ontology, logical expressions, algorithm/workflow

representation

• Connecting with Industry– Showing compelling value– Not promising too much– Providing an incremental path


Next steps / prioritiesFocus on use cases architectureJoint committee forming …Move to OWLModel information servicesProfile: More substantial illustrative taxonomies

Tie in with existing taxonomies where possible (e.g. UNSPSC)

Process ModelEvaluate potential tie-in with an existing effort (WSFL?)

Support real-world useDescribing and using public WSDL servicesPossible collaborations with other SemWeb projectsDemos directed towards Web services community

Tools DAML-S API


(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


SummaryThe service paradigm will be a crucial part of the Semantic WebDAML-S supports service descriptions that are integral with

other Semantic Web meta-dataDAML-S aims to enable automatic discovery, selection,

invocation, composition, monitoring of servicesInitial versions of Profile, Process, and Grounding ontologies

are availableMany challenges remainWe’re interested in synergy with related work



Acknowledgements

• Slides created by David Martin, Sheila McIlraith, Terry Payne

• Ontology images created by Terry Payne, CMU

David Martin for DAML-S Coalition 12/18/2002 DAML-S: Bringing Services to the Semantic Web David Martin SRI International

Documents

damls coalition

damls semantics

damls web service discovery

characteristics of daml

services slide

web slide

service model slide

language development