SlideShare a Scribd company logo
Systems of Systems: Fundamentals, Design, Management Sandeep Purao , Ph.D. Associate Professor of IST  Enterprise Informatics and Integration Center Standards Interest Group, Socio-technical Systems Lab
P O S T Environment System Sub- system Sub- system Sub- system Feedback Entropy Emergence
SoS: Fundamentals Purdue University,  School of  Engineering
The Evolution towards  Systems of Systems Applications Very  large number of ‘nodes’ Under severe stress Changing users Changing composition Changing processes Systems of Systems Application Integration A System of Systems
SoS: An Example An example of complex systems of systems at Hartford Property and Casualty (as of March 2007) Source: Gartner 2007
The key problem We have crossed a threshold where most of our large software ( and socio-technical ) systems can no longer be constructed as monoliths. They are now constructed as groups of interoperating systems (as systems of systems) … made to interoperate through various forms of interfaces.  Fisher 2006 (SEI Tech Report),  Italics Mine
Properties Operational independence of individual systems,  Managerial independence of individual systems,  Geographical distribution,  Emergent behavior, and Evolutionary development (Sage 2001) Distinguishing between POST (plain-old systems thinking) and SoS The importance of ‘platform’ ->   Enterprise Architecture
EA: An Example An example of Enterprise Architecture  at UC Irvine  Source:  UC Irvine http://apps.adcom.uci.edu/EnterpriseArch/index.html
EA as City Planning City Planning City Master Plan Transportation and Utilities Plans Zoning Rules Building Codes Regulatory Guidance Private Building Programs Construction Crews   Enterprise Architecture IT Strategic Plan Major Technology Infrastructure Plan Reference Architectures Approved  Technologies IT Governance Application Architecture Development and Integration (Campbell and Mohun 2007)
Where does EA fit? Demand for IT Supply of IT Enterprise Architecture IT Effectiveness Gap IT Efficiency Gap Business strategy and process requirements Infrastructure, Development and Implementation Business  Architecture Information  Architecture Technology  Architecture Application  Architecture
CSFs for EA Are architecture decisions made at the right levels? Are architecture outputs useful and actionable? Do business/application teams support and use EA? Is leadership actively supporting the effort? Are architecture decisions enforced when appropriate? Is the EA team skilled and is advancing its practices? (Campbell and Mohun 2007)
Measuring EA Value Example Metrics EA Benefit Show EA driven shared infrastructure enabled faster project deployment (case studies) Rapid change enabled Matrix business strategies to projects, show percent of "business aligned" projects (or investments) Improved alignment of IT with the business Show cases where new tech was NOT adopted; some where it was Business-driven introduction of new technology Show use of EA guidance to impact projects (investments) moving forward (qualitative) Direction and guidance for future investments Show quantity of new apps that use implemented shared infrastructure services Better leverage shared infrastructure Show fewer total # standard technologies/products (plus see integration for specific example) Reduction of needless complexity Count them, capture revenue (or other business value) associated with them and aggregate More-effective linkage with external systems Present common before scare and after EAI diagram; count change in # interfaces; # new apps integrated into overall portfolio (versus before) Improved integration between systems  Reuse and repeat of common designs speeds decision making in projects: show less time to complete design, deliver  successful  project Reduced IT solution delivery time
SoS: Building We have crossed a threshold where most of our large software ( and socio-technical ) systems can no longer be constructed as monoliths. They are now constructed as groups of interoperating systems (as systems of systems) … made to interoperate through various forms of interfaces.   Unfortunately, while we can easily conceive these large systems of systems, we have trouble building them
The key role of ‘Process’ Services Processes Value Chain Legacy  App ERP Module Adapted and extended  from: IDS Scheer AG
BPMN (White 2006 – IBM and BPMN.org)
A key Design Abstraction Interaction Patterns as Design Knowledge (Hohpe and Woolfe 2004)
ID Assist: Research Prototype (Umapathy  and Purao  2007)
Evaluation Results Support to use Design Knowledge Complexity of  Design Task Designer  Expertise Design Quality Design Effort + _ (Umapathy and Purao 2007) Yes Yes
SoS: Project Risk Service-oriented Integration Service-oriented Development Business Process Design Service Lifecycle Infrastructure Standards Service Model Governance Process  Portfolio Management Enterprise  Transformation Application Portolios Project-by- Project Project Risks
Research on ISD Risks (Adapted from Mathiassen 2003 and Purao and Mathiassen 2004)
Levels External context  Organizational context Technology context Project context Evolving SoS Characterizing SoS Risks Scott and Vessey 2002
A pilot study Focus: SoS project risks Participants: two organizations Status of integration project Imminent or ongoing Method: Focus groups Multiple stakeholders Audio-recorded  Extensive notes  Cleaned up and analyzed (Purao 2006, Mathiassen 2006)
Pilot study results External Organizational Info System Project Management Users Developers Management is aware of more risks  than Users or Developers.  However, it is the Developers and Users, who will have access to the  detailed information needed to  track events and manage risks. (Purao, Smith and Paul 2007)
Pilot study results Event Perception by Developers Perception by Management Perception by Users Loss of jobs Lack of training Lack of defined  processes The same event is perceived  differently by different groups  of stakeholders
Highlighting selective phases Planning Design Implement’n Operational Management Users Developers Everyone concerned about  Implementation stage.  Not even the developers seem concerned about Design. Broad stages in the project
Pilot study results Realization of the scale, complexity of the project Non-specificity of perceived risks Isolated pockets of over-confidence An a-ha recognition of risks ‘ Hope someone is dealing with this’ Recognition of the socio-technical consequences Quick digression into blaming other stakeholders Calls for decision-makers to ‘pay attention’ to actors
Summary SoS as the New Normal  instead of POST Patterns of Interacting Systems as a new Design Abstraction for building SoS  instead of Algorithms or Components Risks for SoS Projects: Distributed, Emergent not well-researched or well-understood
Our research Zhao, L., Goul, M.,  Purao, S. , Vitharana, P.. 2007. Impacts of service-oriented computing on business and education. Panel at Americas Conference on Information Systems. Robinson, W., and  Purao , S. 2007. Specifying and monitoring commitments in open business processes. Paper under review. K. Umapathy,  Purao , S. 2007. Exploring Alternatives for Representing and Accessing Design Knowledge about Enterprise Integration. International Conference on Conceptual Modeling. Auckland, New Zealand. 2007. Purao , S., Paul, S., and Smith, S. 2007. Understanding enterprise integration project risks: A focus group study. International Workshop on Enterprise Information Systems Engineering 2007. Regensburg, Germany 2007. K. Umapathy,  Purao , S. 2007. Towards a theoretical foundation for web services. IEEE International Conference on Services Computing (SCC) Salt Lake City, Utah. 2007.  Xiaocong, F. Umapathy, K. Yen, J.  Purao , S. 2004. An Agent-based Approach for Interleaved Composition and Execution of Complex Web Services. 23rd International Conference on Conceptual Modeling. Shanghai, China. Cameron , B.,  Purao , S. 2006. Enterprise Systems & Integration Education: Innovative Approaches Utilizing Experience-based Learning. 1st International workshop on Enterprise Systems. Milwaukee, WI. Bagby, J.,  Purao , S., P. Mitra. 2006. Standards Development, Disruptive Innovation and the Nature of Participation: Lock-In, Lock-Out, Holdup. 34th Research Conference on Communication, Information and Internet Policy (TPRC), Washington, DC. Umapathy, K.  Purao , S. Sugumaran, V. 2003. Facilitating Conversations among Web Services as Speech-act based Discourses. 13th Workshop on Information Technologies and Systems. Seattle, WA.

More Related Content

PDF
Architectural approaches for implementing Clinical Decision Support Systems i...
PDF
Comparing "Humane" in European & North American Contexts
PDF
Requirements Engineering for Sustainability - Open Lecture at LUT 2016
PDF
TED Talk - "Lean STS" - Christis
PPTX
TED Talk – Painter – VOSS Team Results
PDF
Eleonora Fiore: Ethical challenges of the Internet of Things in the household...
PDF
Goal Dynamics_From System Dynamics to Implementation
PDF
Lopez
Architectural approaches for implementing Clinical Decision Support Systems i...
Comparing "Humane" in European & North American Contexts
Requirements Engineering for Sustainability - Open Lecture at LUT 2016
TED Talk - "Lean STS" - Christis
TED Talk – Painter – VOSS Team Results
Eleonora Fiore: Ethical challenges of the Internet of Things in the household...
Goal Dynamics_From System Dynamics to Implementation
Lopez

What's hot (12)

PDF
Lecture1 is353-enterprise architectureconcept)
PDF
p346-glowatz
PDF
A comparison of the top four enterprise architecture methodologies
PPTX
WildPackets EMA Whitepaper Preview
PDF
Prerequisites for Continuous Software Engineering
PDF
CRESUS-T: A COLLABORATIVE REQUIREMENTS ELICITATION SUPPORT TOOL
PPTX
Matti rossi prof erp 03102012
PDF
Systemic approach to the Business-IT alignment issue
PPT
Taming the Tech Tiger: Technology Planning in Student Affairs
PDF
Ibm acdemy of technology it complexity
PDF
IRJET- Interface Management and its Effect on Project Complexity in Constr...
PDF
Informatics systems
Lecture1 is353-enterprise architectureconcept)
p346-glowatz
A comparison of the top four enterprise architecture methodologies
WildPackets EMA Whitepaper Preview
Prerequisites for Continuous Software Engineering
CRESUS-T: A COLLABORATIVE REQUIREMENTS ELICITATION SUPPORT TOOL
Matti rossi prof erp 03102012
Systemic approach to the Business-IT alignment issue
Taming the Tech Tiger: Technology Planning in Student Affairs
Ibm acdemy of technology it complexity
IRJET- Interface Management and its Effect on Project Complexity in Constr...
Informatics systems
Ad

Viewers also liked (10)

PPT
Unlocking the value of health data - Presentation at the Congressional Lunche...
PPTX
Three generations of systems and design thinking
PPTX
A Viable System Model Approach to the Organisational Structure of the Informa...
PPTX
The Data Warehouse Lifecycle
PDF
Microsoft Data Warehouse Business Intelligence Lifecycle - The Kimball Approach
PDF
SYSTEMS THINKING: Lessons From The Fifth Discipline Fieldbook by Senge, Kleik...
PPTX
Design Tools for Systems Thinking
PDF
Complexity Thinking
PDF
Lecture on Service Design and Design Thinking Management Center Innsbruck 2009
PPTX
Intro to Systems Thinking
Unlocking the value of health data - Presentation at the Congressional Lunche...
Three generations of systems and design thinking
A Viable System Model Approach to the Organisational Structure of the Informa...
The Data Warehouse Lifecycle
Microsoft Data Warehouse Business Intelligence Lifecycle - The Kimball Approach
SYSTEMS THINKING: Lessons From The Fifth Discipline Fieldbook by Senge, Kleik...
Design Tools for Systems Thinking
Complexity Thinking
Lecture on Service Design and Design Thinking Management Center Innsbruck 2009
Intro to Systems Thinking
Ad

Similar to Systems of Systems - Design and Management (20)

PDF
A Design Theory For Digital Platforms Supporting Online Communities A Multip...
PPT
Supporting Software Development Teams with a Semantic Process- and Artifact-o...
PDF
A Study of the Evolution Process of PaaS Ecosystem -Abridged Edition-
PPT
EA as an Actionable Architecture
PDF
Climbing the tree of unreachable fruits, reusing processes
PDF
ITERATIVE AND INCREMENTAL DEVELOPMENT ANALYSIS STUDY OF VOCATIONAL CAREER INF...
PPT
Actionable Architecture
PDF
Article32 SWOT ANALYSIS OF ONTOLOGY DRIVEN SOFTWARE ENGINEERING
PPT
The Challenges Of, And Advantages In, Establishing A Consistent Architectural...
DOCX
Software engineering
PDF
DEVELOPMENT OF A MULTIAGENT BASED METHODOLOGY FOR COMPLEX SYSTEMS
PDF
Vijayananda Mohire-dissertation-abstract
PPT
Strategies-Developing-Deploying-FOSS
PDF
The impact of system quality and user participation on business intelligence ...
PPTX
SYSTEM ANALYSIS AND DESIGN IN LIBRARIES AND INFORMATION CENTERS.pptx
PPT
When Users Becom Collaborators: Towards Continuous and Context-Aware User Input
PPT
Cultivating Sustainable Software For Research
DOCX
RUNNING HEADER Analytics Ecosystem1Analytics Ecosystem4.docx
PPTX
Basics of se
PPTX
Thoughts On Architecting V4 2
A Design Theory For Digital Platforms Supporting Online Communities A Multip...
Supporting Software Development Teams with a Semantic Process- and Artifact-o...
A Study of the Evolution Process of PaaS Ecosystem -Abridged Edition-
EA as an Actionable Architecture
Climbing the tree of unreachable fruits, reusing processes
ITERATIVE AND INCREMENTAL DEVELOPMENT ANALYSIS STUDY OF VOCATIONAL CAREER INF...
Actionable Architecture
Article32 SWOT ANALYSIS OF ONTOLOGY DRIVEN SOFTWARE ENGINEERING
The Challenges Of, And Advantages In, Establishing A Consistent Architectural...
Software engineering
DEVELOPMENT OF A MULTIAGENT BASED METHODOLOGY FOR COMPLEX SYSTEMS
Vijayananda Mohire-dissertation-abstract
Strategies-Developing-Deploying-FOSS
The impact of system quality and user participation on business intelligence ...
SYSTEM ANALYSIS AND DESIGN IN LIBRARIES AND INFORMATION CENTERS.pptx
When Users Becom Collaborators: Towards Continuous and Context-Aware User Input
Cultivating Sustainable Software For Research
RUNNING HEADER Analytics Ecosystem1Analytics Ecosystem4.docx
Basics of se
Thoughts On Architecting V4 2

More from Sandeep Purao (12)

PPT
Keynote at Doctoral Consortium - CAiSE 2013 - Valencia Spain
PPT
A Personal View on Research and Writing
PPT
Re-using Integration Patterns as Design Knowledge
PPT
Problem Solving Process
PPT
Technology Choices for Enterprise Integration
PPT
Introduction to a Course in Advanced Enterprise Integration
PPT
Standards and Standardization - A Research Project
PPT
SOA Methodologies in Practice
PPT
Standardization: Overcoming Design by Committee
PPT
Using Problems to learn Service-oriented Computing
PPT
DESRIST 2008 Doctoral Consortium Report
PPT
The overlaps between Action Research and Design Research
Keynote at Doctoral Consortium - CAiSE 2013 - Valencia Spain
A Personal View on Research and Writing
Re-using Integration Patterns as Design Knowledge
Problem Solving Process
Technology Choices for Enterprise Integration
Introduction to a Course in Advanced Enterprise Integration
Standards and Standardization - A Research Project
SOA Methodologies in Practice
Standardization: Overcoming Design by Committee
Using Problems to learn Service-oriented Computing
DESRIST 2008 Doctoral Consortium Report
The overlaps between Action Research and Design Research

Recently uploaded (20)

PPTX
VMware vSphere Foundation How to Sell Presentation-Ver1.4-2-14-2024.pptx
PDF
Reach Out and Touch Someone: Haptics and Empathic Computing
PPT
Teaching material agriculture food technology
PDF
Encapsulation_ Review paper, used for researhc scholars
PDF
Approach and Philosophy of On baking technology
PDF
Empathic Computing: Creating Shared Understanding
PDF
TokAI - TikTok AI Agent : The First AI Application That Analyzes 10,000+ Vira...
PDF
Machine learning based COVID-19 study performance prediction
PPTX
Digital-Transformation-Roadmap-for-Companies.pptx
PPT
“AI and Expert System Decision Support & Business Intelligence Systems”
PDF
Bridging biosciences and deep learning for revolutionary discoveries: a compr...
PPTX
20250228 LYD VKU AI Blended-Learning.pptx
PDF
NewMind AI Monthly Chronicles - July 2025
PPTX
PA Analog/Digital System: The Backbone of Modern Surveillance and Communication
PDF
Mobile App Security Testing_ A Comprehensive Guide.pdf
PDF
KodekX | Application Modernization Development
PDF
Diabetes mellitus diagnosis method based random forest with bat algorithm
PDF
cuic standard and advanced reporting.pdf
PDF
Unlocking AI with Model Context Protocol (MCP)
PDF
Electronic commerce courselecture one. Pdf
VMware vSphere Foundation How to Sell Presentation-Ver1.4-2-14-2024.pptx
Reach Out and Touch Someone: Haptics and Empathic Computing
Teaching material agriculture food technology
Encapsulation_ Review paper, used for researhc scholars
Approach and Philosophy of On baking technology
Empathic Computing: Creating Shared Understanding
TokAI - TikTok AI Agent : The First AI Application That Analyzes 10,000+ Vira...
Machine learning based COVID-19 study performance prediction
Digital-Transformation-Roadmap-for-Companies.pptx
“AI and Expert System Decision Support & Business Intelligence Systems”
Bridging biosciences and deep learning for revolutionary discoveries: a compr...
20250228 LYD VKU AI Blended-Learning.pptx
NewMind AI Monthly Chronicles - July 2025
PA Analog/Digital System: The Backbone of Modern Surveillance and Communication
Mobile App Security Testing_ A Comprehensive Guide.pdf
KodekX | Application Modernization Development
Diabetes mellitus diagnosis method based random forest with bat algorithm
cuic standard and advanced reporting.pdf
Unlocking AI with Model Context Protocol (MCP)
Electronic commerce courselecture one. Pdf

Systems of Systems - Design and Management

  • 1. Systems of Systems: Fundamentals, Design, Management Sandeep Purao , Ph.D. Associate Professor of IST Enterprise Informatics and Integration Center Standards Interest Group, Socio-technical Systems Lab
  • 2. P O S T Environment System Sub- system Sub- system Sub- system Feedback Entropy Emergence
  • 3. SoS: Fundamentals Purdue University, School of Engineering
  • 4. The Evolution towards Systems of Systems Applications Very large number of ‘nodes’ Under severe stress Changing users Changing composition Changing processes Systems of Systems Application Integration A System of Systems
  • 5. SoS: An Example An example of complex systems of systems at Hartford Property and Casualty (as of March 2007) Source: Gartner 2007
  • 6. The key problem We have crossed a threshold where most of our large software ( and socio-technical ) systems can no longer be constructed as monoliths. They are now constructed as groups of interoperating systems (as systems of systems) … made to interoperate through various forms of interfaces. Fisher 2006 (SEI Tech Report), Italics Mine
  • 7. Properties Operational independence of individual systems, Managerial independence of individual systems, Geographical distribution, Emergent behavior, and Evolutionary development (Sage 2001) Distinguishing between POST (plain-old systems thinking) and SoS The importance of ‘platform’ -> Enterprise Architecture
  • 8. EA: An Example An example of Enterprise Architecture at UC Irvine Source: UC Irvine http://apps.adcom.uci.edu/EnterpriseArch/index.html
  • 9. EA as City Planning City Planning City Master Plan Transportation and Utilities Plans Zoning Rules Building Codes Regulatory Guidance Private Building Programs Construction Crews Enterprise Architecture IT Strategic Plan Major Technology Infrastructure Plan Reference Architectures Approved Technologies IT Governance Application Architecture Development and Integration (Campbell and Mohun 2007)
  • 10. Where does EA fit? Demand for IT Supply of IT Enterprise Architecture IT Effectiveness Gap IT Efficiency Gap Business strategy and process requirements Infrastructure, Development and Implementation Business Architecture Information Architecture Technology Architecture Application Architecture
  • 11. CSFs for EA Are architecture decisions made at the right levels? Are architecture outputs useful and actionable? Do business/application teams support and use EA? Is leadership actively supporting the effort? Are architecture decisions enforced when appropriate? Is the EA team skilled and is advancing its practices? (Campbell and Mohun 2007)
  • 12. Measuring EA Value Example Metrics EA Benefit Show EA driven shared infrastructure enabled faster project deployment (case studies) Rapid change enabled Matrix business strategies to projects, show percent of "business aligned" projects (or investments) Improved alignment of IT with the business Show cases where new tech was NOT adopted; some where it was Business-driven introduction of new technology Show use of EA guidance to impact projects (investments) moving forward (qualitative) Direction and guidance for future investments Show quantity of new apps that use implemented shared infrastructure services Better leverage shared infrastructure Show fewer total # standard technologies/products (plus see integration for specific example) Reduction of needless complexity Count them, capture revenue (or other business value) associated with them and aggregate More-effective linkage with external systems Present common before scare and after EAI diagram; count change in # interfaces; # new apps integrated into overall portfolio (versus before) Improved integration between systems Reuse and repeat of common designs speeds decision making in projects: show less time to complete design, deliver successful project Reduced IT solution delivery time
  • 13. SoS: Building We have crossed a threshold where most of our large software ( and socio-technical ) systems can no longer be constructed as monoliths. They are now constructed as groups of interoperating systems (as systems of systems) … made to interoperate through various forms of interfaces. Unfortunately, while we can easily conceive these large systems of systems, we have trouble building them
  • 14. The key role of ‘Process’ Services Processes Value Chain Legacy App ERP Module Adapted and extended from: IDS Scheer AG
  • 15. BPMN (White 2006 – IBM and BPMN.org)
  • 16. A key Design Abstraction Interaction Patterns as Design Knowledge (Hohpe and Woolfe 2004)
  • 17. ID Assist: Research Prototype (Umapathy and Purao 2007)
  • 18. Evaluation Results Support to use Design Knowledge Complexity of Design Task Designer Expertise Design Quality Design Effort + _ (Umapathy and Purao 2007) Yes Yes
  • 19. SoS: Project Risk Service-oriented Integration Service-oriented Development Business Process Design Service Lifecycle Infrastructure Standards Service Model Governance Process Portfolio Management Enterprise Transformation Application Portolios Project-by- Project Project Risks
  • 20. Research on ISD Risks (Adapted from Mathiassen 2003 and Purao and Mathiassen 2004)
  • 21. Levels External context Organizational context Technology context Project context Evolving SoS Characterizing SoS Risks Scott and Vessey 2002
  • 22. A pilot study Focus: SoS project risks Participants: two organizations Status of integration project Imminent or ongoing Method: Focus groups Multiple stakeholders Audio-recorded Extensive notes Cleaned up and analyzed (Purao 2006, Mathiassen 2006)
  • 23. Pilot study results External Organizational Info System Project Management Users Developers Management is aware of more risks than Users or Developers. However, it is the Developers and Users, who will have access to the detailed information needed to track events and manage risks. (Purao, Smith and Paul 2007)
  • 24. Pilot study results Event Perception by Developers Perception by Management Perception by Users Loss of jobs Lack of training Lack of defined processes The same event is perceived differently by different groups of stakeholders
  • 25. Highlighting selective phases Planning Design Implement’n Operational Management Users Developers Everyone concerned about Implementation stage. Not even the developers seem concerned about Design. Broad stages in the project
  • 26. Pilot study results Realization of the scale, complexity of the project Non-specificity of perceived risks Isolated pockets of over-confidence An a-ha recognition of risks ‘ Hope someone is dealing with this’ Recognition of the socio-technical consequences Quick digression into blaming other stakeholders Calls for decision-makers to ‘pay attention’ to actors
  • 27. Summary SoS as the New Normal instead of POST Patterns of Interacting Systems as a new Design Abstraction for building SoS instead of Algorithms or Components Risks for SoS Projects: Distributed, Emergent not well-researched or well-understood
  • 28. Our research Zhao, L., Goul, M., Purao, S. , Vitharana, P.. 2007. Impacts of service-oriented computing on business and education. Panel at Americas Conference on Information Systems. Robinson, W., and Purao , S. 2007. Specifying and monitoring commitments in open business processes. Paper under review. K. Umapathy, Purao , S. 2007. Exploring Alternatives for Representing and Accessing Design Knowledge about Enterprise Integration. International Conference on Conceptual Modeling. Auckland, New Zealand. 2007. Purao , S., Paul, S., and Smith, S. 2007. Understanding enterprise integration project risks: A focus group study. International Workshop on Enterprise Information Systems Engineering 2007. Regensburg, Germany 2007. K. Umapathy, Purao , S. 2007. Towards a theoretical foundation for web services. IEEE International Conference on Services Computing (SCC) Salt Lake City, Utah. 2007. Xiaocong, F. Umapathy, K. Yen, J. Purao , S. 2004. An Agent-based Approach for Interleaved Composition and Execution of Complex Web Services. 23rd International Conference on Conceptual Modeling. Shanghai, China. Cameron , B., Purao , S. 2006. Enterprise Systems & Integration Education: Innovative Approaches Utilizing Experience-based Learning. 1st International workshop on Enterprise Systems. Milwaukee, WI. Bagby, J., Purao , S., P. Mitra. 2006. Standards Development, Disruptive Innovation and the Nature of Participation: Lock-In, Lock-Out, Holdup. 34th Research Conference on Communication, Information and Internet Policy (TPRC), Washington, DC. Umapathy, K. Purao , S. Sugumaran, V. 2003. Facilitating Conversations among Web Services as Speech-act based Discourses. 13th Workshop on Information Technologies and Systems. Seattle, WA.