Semantic Web Services Initiative Architecture Committee

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Semantic Web Services InitiativeArchitecture
Committee

• co-chaired by
• Mark BursteinBBN Technologies
• Christoph Bussler Digital Enterprise Research
  Institute (DERI)

2
Committee Members

• Bob Balzer, Teknowledge, Inc. (Los Angeles)
• Boualem Benatallah, University of South Wales,
  Australia
• Fabio Casati, HP Labs (Palo Alto)
• Mike Dean, BBN Technologies
• Tim Finin, University of Maryland, Baltimore
  County
• Carole Goble, University of Manchester, UK
• Michael Huhns, University of South Carolina
• Atanas Kiryakov, Sirma Ltd., Bulgaria
• Enrico Motta, Open University, UK
• John Mylopolous, University of Toronto
• Massimo Paolucci, Carnegie Mellon University
• Norman Sadeh, Carnegie Mellon University (new)
• Dan Weld, University of Washington (withdrawn)
• Stuart Williams, HP Labs (Bristol, UK)
• Others?

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SWSA Mission Statement

• The mission of the SWSI Architecture Committee
  (SWSA) is to develop architectural and protocol
  abstractions forming a reference architecture to
  support Semantic Web Service technologies.
• Develop use cases to demonstrate the benefits of
  using machine interpretable semantics to
  facilitate dynamic interoperability,
  composability, and substitutability among web
  services and for agent-based services in other
  distributed environments.
• Promote the development of standards,
  methodological and theoretical underpinnings
  through discussions, publications, reference
  implementations and coordination with standards
  bodies.

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Objectives

1. To identify, through use case analysis, a set of
   key functional elements needed to enable semantic
   web service capabilities, such as dynamic
   interoperability and compositionality, and to
   enumerate requirements for the implementation of
   these functions in different architectural
   environments.
2. To develop abstract protocols for interaction
   with the middleware functions delineated in (1)
   to support semantic web services. These protocols
   should be realizable in the specification
   language(s) developed by the SWSI Language
   committee.

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Tasks

• (0) Identify common functionalities required to
  support semantic web services.
• Develop use cases in different operational
  environments that identify protocol
  requirements and alternative software
  architectures for distributing the support
  functions described in (0).
• Develop abstract protocols for the identified
  support functions. Work with the SWSL committee
  to represent these protocols in the language(s)
  they develop.
• Determine the feasibility of implementing these
  service support functions as extensions of the
  W3C WS reference architecture.
• Develop small exploratory prototypes to validate
  the concepts developed.

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Milestones

• 1. Working draft of document covering
  requirements and 4 key Use Cases by November
  2003.
• 2. Working draft of abstract protocols for SWS
  architectural support functions by June 2004.
• 3. Development of a coordinated SWSI submission
  to W3C by Q1, 2005

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Diverse Set of Usage Scenarios to Capture
Variability in Requirements

• Coverage of five major areas of potential use of
  semantic web services
• B2B and Enterprise Integration Systems
• Grid Computing
• Ubiquitous Computing
• B2C and End User (personal agent) Web Services
• Agent-based Systems in large organizations

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Within Scenarios, Use Cases to Cover a Range of
Applicable Core Functions

• a)   Service request planning and response
  interpretation (based on process descriptions)
• b)   Choreography (protocol) interpretation and
  execution
• c)   Semantic translation/mediation (e.g., of
  message content, process descriptions or
  advertisments)
• d)   Candidate service discovery (mediated)
• e) Candidate service selection (negotiated)
• f)   Automated Process composition
• g)    Process mediation and delegation

• h)   Service process status tracking
• i)   Ontology management and access
• j)    Security (including identification,
  authentication, policy-based authorization)
• k)    Reputation services
• l)   Service failure handling and compensation
• m)    Negotiation and contracting
• n)  Server executable process management (service
  factories, instantiation, migration)

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Use Cases Under Development

• Discovery and Invocation for B2C Web Services
• Discovery and Security/Privacy Policies in
  Ubiquitious Computing
• Semantics for Composition, Service Resource
  Management in Grid Computing
• Contract Negotiation and Ontology, Ontology Map
  Management for Interoperability maintenance in
  B2B

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Identify Important Functionalities in Each
Environment
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Example GRID

• The services to be delivered primarily relate to
  service executions, however may involve hardware
  services in the future.
• 1.1        Functional requirements for OGSA
  platform
• This use case uses the following OGSA
  functionalities as described in 1
• 1.      Discovery.
• 2.       Workflow management.
• 3.       Scheduling of service tasks.
• 4.       Disaster Recovery.
• 5.       Provisioning.
• 6.       Brokering.
• 7.       Load Balancing.
• 8.       Fault Tolerance.
• 9.       Transport Management.
• 10.   Legacy Application Management.
• 11.   Services Facilitating Brokering.
• 12.   Application and Network-level Firewalls.
• 13.   Agreement-based interation. Authorization
  and use policies.

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Wheres the Semantics?

• Identify the role that semantics could play in
  improving the capabilities of each functional
  area.
• Identify support elements required to provide
  that capability.
• Identify protocols and language requirements.

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Goals for the Meeting Today

• Discuss each of the Use Cases currently under
  development
• What are the architectural issues involved?
• What (abstract) protocols should be standardized?
• Are there requirements on languages that arise
  from this?
• Develop draft list of requirements
• Do we want to assume particular underlying
  architectural layers?
• Develop outline and writing assignments for
  Requirements Document draft.

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Overall Agenda

• 900 - 910 Opening Remarks (Katia)910 -
  940 Language Committee Report
  (Kifer/Martin)940 -1010 Architecture
  Report (Burstein/Bussler)1010 - 1020
  Industrial Board (Davies/Grosof/Uschold)1020 -
  1045 Break1045 - 1230 Parallel Working
  Sessions for the two committeesSWSA
  Presentation and Discussion of Use Cases1230 -
  1330 Lunch1330 - 1530 Parallel Working
  Sessions for the two committeesSWSA Discussion
  of Candidate Requirements
• 1530 - 1600 Break1600 - 1700 Parallel
  Working Sessions for the two committeesSWSA
  Outlining of Requirements Document and
  Assignments1700 - 1730 Out brief of the two
  committees (15 minutes each)1730 - 1800
  Management Session              --determining
  the action items and plans for the future

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What we did during this F2F

• Reviewed mapping of SWS environments against key
  functions, developed matrix identifying where
  each was critical, likely to be required, or not.
• Refined list of functions, refined definition of
  each functional area, with examples.
• Developed outline for use cases
• Postponed finalizing outline for requirements
  document to next telecon after ISWC.

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Use Cases Under Development

• Discovery and Invocation for B2C Web Services
  -Massimo
• Discovery and Security/Privacy Policies in
  Ubiquitious Computing Tim, Stuart, Norman
• Semantics for Composition, Service Resource
  Management in Grid Computing - Carol
• Contract Negotiation and Ontology, Ontology Map
  Management for Interoperability maintenance in
  B2B - Chris
• use case repository at http//www.daml.org/ser
  vices/use-cases/architecture

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Reviewed Range of Core Functions

• a)   Service request planning and response
  interpretation (based on process descriptions)
• b)   Choreography (protocol) interpretation and
  execution
• c)   Semantic translation/mediation (e.g., of
  message content, process descriptions or
  advertisments)
• d)   Candidate service identification
  (matchmaking) and selection
• e)   Automated Process composition
• f)    Process mediation and delegation
• g)   Service process status tracking
• h)   Ontology management and access

• i)    Security (including identification,
  authentication, delegation and policy-based
  authorization)
• j)    Reputation services
• k)   Service failure handling and compensation
• l)    Negotiation and contracting
• m)  Server executable process management (service
  factories, instantiation, migration)

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Refined List of Functions

• a)       Service invocation message formulation
  and response interpretation
• -          Atomic parameterized grounded
  invocation of a service operation from a services
  description
• E.g. Identification of required input
  values for a P.O. message to SAP, execution of
  the grounding
• b)       Choreography (protocol) interpretation
  and execution
• -          Execution of the interaction protocol
  of one service. Attribution of semantics to set
  of temporally related messages.
• -          E.g. protocol descriptions could be
  described by UML sequence diagrams
• -          E.g. Request, Acknowledgement of a PO
• Choreography interpretation of multi-service
  interactions
• c)      Semantic translation/mediation (e.g., of
  message content, process descriptions or
  advertisements)
• d)      Candidate service discovery via
  directory, broker or referral
• -         In U.C. find a printer when you walk
  into a room (referral by broker or peer)
• e)      Service Selection (by negotiation
  directly with candidate services)
• -         Refining requirements
• -         eg auctions
• f)        Automated Process composition
  (planning, creation of a choreography, writing of
  a program)
• g)      Process mediation and delegation
• -         mediating between two service
  descriptions or choreographies
• h)     

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Continued

• SeService process status tracking/monitoring vs
  event notification
• i)        Ontology management and access
• j)        Security (including identification,
  authentication, delegation and policy-based
  authorization)
• k)  Reputation services
• l Service failure handling and compensation
• m)    Negotiation and contracting
• n)      Server executable process management
  (service factories, instantiation, migration,
  liveness)
• o)     
• NEW
• Resource Allocation/Provisioning
• p)      Dispute Resolution and Compliance
• q)      Privacy and Confidentiality
• r)       Usability (by humans) - includes HCI
• s)       Non-Repudiation/ Audit
  Tracking/Explanation

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Matrix of Requirements to Use Cases