Service-Oriented Computing - ICSOC 2006: 4th International Conference, Chicago, IL, USA, December 4-7, Proceedings

Lecture Notes in Computer Science Commenced Publication in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen

Editorial Board David Hutchison Lancaster University, UK Takeo Kanade Carnegie Mellon University, Pittsburgh, PA, USA Josef Kittler University of Surrey, Guildford, UK Jon M. Kleinberg Cornell University, Ithaca, NY, USA Friedemann Mattern ETH Zurich, Switzerland John C. Mitchell Stanford University, CA, USA Moni Naor Weizmann Institute of Science, Rehovot, Israel Oscar Nierstrasz University of Bern, Switzerland C. Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen University of Dortmund, Germany Madhu Sudan Massachusetts Institute of Technology, MA, USA Demetri Terzopoulos University of California, Los Angeles, CA, USA Doug Tygar University of California, Berkeley, CA, USA Moshe Y. Vardi Rice University, Houston, TX, USA Gerhard Weikum Max-Planck Institute of Computer Science, Saarbruecken, Germany

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Asit Dan Winfried Lamersdorf (Eds.)

Service-Oriented Computing – ICSOC 2006 4th International Conference Chicago, IL, USA, December 4-7, 2006 Proceedings

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Volume Editors Asit Dan IBM T.J. Watson Research Center 19, Skyline Drive, Hawthorne, NY, 10532, USA E-mail: [email protected] Winfried Lamersdorf University of Hamburg Distributed Systems and Information Systems, Computer Science Department Vogt-Kölln-Str. 30, 22527 Hamburg, Germany E-mail: [email protected]

Library of Congress Control Number: 2006937445 CR Subject Classification (1998): C.2, D.2, D.4, H.4, H.3, K.4.4 LNCS Sublibrary: SL 2 – Programming and Software Engineering ISSN ISBN-10 ISBN-13

0302-9743 3-540-68147-7 Springer Berlin Heidelberg New York 978-3-540-68147-2 Springer Berlin Heidelberg New York

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Preface

This volume contains the proceedings of the 4th International Conference on ServiceOriented Computing (ICSOC 2006), which took place in Chicago, USA, December 4–7, 2006. ICSOC 2006 followed on the success of three previous editions of the International Conference on Service-Oriented Computing in Amsterdam, Netherlands (2005), New York City, USA (2004) and Trento, Italy (2003). ICSOC is recognized as the main conference for service-oriented computing research that covers the entire spectrum from theoretical and foundational results to empirical evaluations as well as practical and industrial experiences. ICSOC 2006 built on that foundation while introducing several innovations in furthering this goal. Service-oriented computing brings together ideas and technologies from many different fields in an evolutionary manner to address research challenges such as service composition, discovery, integration, monitoring and management of services, service quality and security, methodologies for supporting service development, governances in their evolution, as well as their overall life-cycle management. ICSOC 2006 strengthened the link to two important communities, Software Engineering and Grid Computing, with well-known leaders from these communities serving in important organizing roles such as general chairs in shaping the conference. In order to provide a balanced coverage and equal emphasis on all SOC topics, these topics are divided into six major areas. They include Business Service Modeling, Service Assembly, Service Deployment, and Management – covering the research issues in the four primary life-cycle phases of a service, modeling, assembly, deployment, and management. Additionally, the runtime architectural issues are covered by the SOA Runtime, and quality of service issues – spanning all life-cycle stages, i.e., specification to autonomic management – are covered by the Quality of Service area. Finally, the Grid Services area covers application of service-oriented computing in managing infrastructural resources. Organizationally, for each of these areas, respective Area Coordinators have the key role of defining topics, reaching out to the scientific communities and supporting the evaluation and selection of papers related to the diverse communities. The paper selection process was very thorough. Matching diversity of paper topics and reviewer expertise is definitely a challenge. Therefore, we worked closely with the Area Coordinators, i.e., two experts representing each of the areas, to assign reviewers to submitted papers, and also to sort out the differences in opinions from different reviewers by weighing in their expert opinion. Since the content of a paper may be identified by multiple areas, reviewers were drawn from all the associated areas. Overall in the selection process, we sought a diversity of papers and balance across the areas while selecting the top papers in each of the areas. ICSOC 2006 received over 200 contributions in the research track, accepting only 34 full and 16 short papers.

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Preface

This year we also enhanced the industrial track by attracting many industry leaders – representing the gamut of software middleware vendors, consulting analysts, solution integrators and practitioners of service-oriented architecture (SOA) – both to serve on the Program Committee and to submit papers sharing valuable hands-on experiences and key challenges in practicing service-oriented computing. The industrial papers highlight lessons learned, analysis of technology gap, methodology used in practice, noteworthy and innovative application scenarios, need for new standardization, and major improvements to the state of practice. The industry track received more than 60 submissions, out of which only 9 full papers were selected. It also features two invited vision papers discussing the evolution of service-oriented computing. In addition to the regular, industry, and short presentations, the ICSOC 2006 conference featured three tutorials, two panels examining the role of open-source software and research challenges, and – as customary in ICSOC conferences – top-notch keynotes, given by leaders in the industrial and academic community. The excellent program that we assembled for presentation at the conference is a reflection of the hard and dedicated work of numerous people. We would like to thank the members of the Program Committee and the reviewers for their great efforts in selecting the papers, and the Area Coordinators in making an extra effort in looking over the reviews and sorting out differences in opinions. We also acknowledge the great contributions of Julie Wulf-Knoerzer in the local organization, of Vincenzo D’Andrea for handling finances, of Matei Ripeanu in handling the publicity, of Boualem Benatallah for handling publication of the conference proceedings, and of Martin Swany for handling registration. We also thank Dimitrios Georgakopoulos, Norbert Ritter (Workshop Chairs), Frank Leymann and Heiko Ludwig (Tutorial Chairs) for organizing associated workshops and tutorials. We would also like to thank some individuals for their special help and contributions: Sonja Zaplata for assisting the Program Chairs in tracking various issues that arose throughout the review process, and for being prompt in responding to queries from authors, reviewers and other conference chairs, Harald Weinreich, who created and adapted the conftool for us several times – often without anyone really noticing––and Anne Awizen for her support. And last but not the least, we would like to thank the Steering Committee members, Fabio Casati, Paco Curbera, Mike Papazoglou, and Paolo Traverso, for their guidance, and our partners, ACM SIGWeb and SIGSoft. We hope you find the papers in this volume interesting and stimulating.

December 2006

Ian Foster and Carlo Ghezzi (General Chairs) Asit Dan and Winfried Lamersdorf (Program Chairs) Robert Johnson, and Jeff Mischkinsky (Industrial Track Chairs)

Organization

ICSOC 2006 Conference Chairs General Chairs Program Chairs Industrial Track Chairs Workshop Coordination Tutorial Chairs Local Arrangements Chair Financial Chair Registration Chair Publicity Chair Publication Chair Steering Committee

Ian Foster, University of Chicago, USA Carlo Ghezzi, Politecnico di Milano, Italy Asit Dan, IBM, USA Winfried Lamersdorf, Hamburg University, Germany Robert Johnson, IBM, USA Jeff Mischkinsky, Oracle, USA Dimitrios Georgakopoulos, Telcordia, USA Norbert Ritter, Hamburg University, Germany Frank Leymann, University of Stuttgart, Germany Heiko Ludwig, IBM, USA Julie Wulf, Univa Corporation, USA Vincenzo D’Andrea, University of Trento, Italy Martin Swany, University of Delaware, USA Matei Ripeanu, University of British Columbia, Canada Boualem Benatallah, UNSW, Australia Fabio Casati, Hewlett-Packard Labs, USA Paco Curbera, IBM Research, Hawthorne, UK Mike Papazoglou, Tilburg University, Netherlands Paolo Traverso, ITC-IRST, Italy

Area Coordinators Service Modeling Service Assembly Service Management SOA Runtime Quality of Service Grid Services

Wolfgang Emmerich, UCL, UK Mathias Weske, University of Potsdam, Germany Barbara Pernici, Politecnico di Milano, Italy Munindar Singh, North Carolina State University, USA Luciano Baresi , Politecnico di Milano, Italy Hiro Kishimoto, Jujitsu, Japan Douglas Schmidt, Vanderbilt University, USA Steve Vinoski, Iona, USA Priya Narasimhan, CMU, USA Jim Pruyne, HP, USA Dennis Gannon, Indiana University, USA Paul Watson, Univ. of Newcastle upon Tyne, UK

Program Committee

Research Track Nabil R. Adam Jose Luis Ambite Mikio Aoyama Alistair Barros Boualem Benatallah Walter Binder Athman Bouguettaya Sjaak Brinkkemper Tevfik Bultan Fabio Casati Malu Castellanos Bruno Crispo Paco Curbera Vincenzo D'Andrea Umesh Dayal Flavio De Paoli Tommaso Di Noia Jens-Peter Dittrich John Domingue Schahram Dustdar Boi Faltings Dieter Fensel Gianluigi Ferrari George Feuerlicht Ioannis Fikouras Geoffrey Fox Alex Galis Dimitrios Georgakopoulos Paolo Giorgini Claude Godart Paul Grefen John Grundy Mohand-Said Hacid Hakan Hacigumus Kate Keahey Alfons Kemper Roger Kilian-Kehr Jana Koehler Bernd Kraemer Brian LaMacchia Frank Leymann

Rutgers University, USA USC/ISI, USA NISE, Japan SAP, Australia University of New South Wales, Australia EPFL, Switzerland Virginia Tech, USA Utrecht University, Netherlands UCSB, USA HP, USA HP, USA Vrije University Amsterdam, Netherlands IBM Research, USA Università di Trento, Italy HP, USA Università di Milano, Italy University of Bari, Italy ETH Zurich, Switzerland KMI, UK University of Technology Vienna, Austria EPFL, Switzerland University of Innsbruck, Austria University of Pisa, Italy University of Technology Sydney, Australia Ericsson, Germany Indiana University, USA UCL, UK Telcordia, USA University of Trento, Italy Université Henri Poincaré Nancy, France Eindhoven University of Technology, Netherlands University of Auckland, New Zealand Université Lyon, France Almaden IBM, USA Argonne National Laboratory, USA Technische Universität München, Germany SAP Karlsruhe, Germany IBM Zurich Research Lab, Switzerland Fernuniversität Hagen, Germany Microsoft, USA University of Stuttgart, Germany

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Organization

Ling Liu Heiko Ludwig Neil Maiden Tiziana Margarina Ioana Manolescu David Martin Eugene M. Maximilien Massimo Mecella Brahim Medjahed Toshiyuki Nakata Christos Nikolaou David O'Hallaron Guadalupe Ortiz Mike Papazoglou Anna Perini Marco Pistore Axel Polleres Jean Pierre Prost Omer Rana Thomas Risse Norbert Ritter Colette Rolland Rainer Ruggaber Akhil Sahai Volker Sander Vladimiro Sassone, Dimitrios N. Serpanos Jun Shen Santosh Srivastava Maarten Steen Tony Storey Jianwen Su Ravi Subramaniam Angelo Susi Katia Sycara Stefan Tai Kian-Lee Tan Paolo Tonella Farouk Toumani Don Towsley Paolo Traverso Aphrodite Tsalgatidou Karthikeyan Umapathy Will van der Aalst Jos van Hillegersberg Aad Van Moorsel Vijay Varadharajan John Wilkes Martin Wirsing

Georgia Institute of Technology, USA IBM Research, USA City University London, UK Potsdam University, Germany INRIA, France SRI, USA IBM Almaden, USA Università di Roma, Italy Michigan University, USA NEC, Japan University of Crete, Greece Carnegie Mellon University, USA Universidad de Extremadura, Spain Tilburg University, Netherlands ITC-IRST Trento, Italy Università di Trento, Italy Universidad Rey Juan Carlos, Spain IBM Montpellier, France Cardiff University, UK Fraunhofer Gesellschaft, Germany Hamburg University, Germany Université de Paris I, France SAP, Germany HP, USA Jülich Research Centre, Germany University of Southampton, UK University of Patras, Greece University of Wollongong, Australia University of New Castle, UK Telematica Enschede, Netherlands IBM, UK UCSB, USA Intel, USA ITC-IRST Trento, Italy CMU, USA IBM New York, USA National University of Singapore, Singapore ITC-IRST Trento, Italy ISIMA Autiere, France University of Massachusetts, USA ITC-RST, Italy University of Athens, Greece Penn State University, USA Eindhoven University of Technology, Netherlands University of Twente, Netherlands University of Newcastle, UK Macquarie University, Australia HP Labs Palo Alto, USA Technische Universität München, Germany

Organization

Jian Yang Arkady Zaslavsky Gianluigi Zavattaro Yanchun Zhang Christian Zirpins

Macquiri University, Australia Monash University Melbourne, Australia University of Bologna, Italy Victoria University, Australia University College London, UK

Industry Track Anne Anderson Paul Fremantle Steve Graham Frederick Hirsch Kerrie Holley Philippe Le Hégaret Mark Little Ashok Malhotra Andy Mulholland Srinivas Narayanan Eric Newcomer Mark Nottingham Sanjay Patil Greg Pavlik Harini Srinivasan William Vambenepe Sanjiva Weerawarana Bobbi Young

Sun, USA WSO2, UK IBM, USA Nokia, USA IBM, USA W3C, USA Redhat, USA Oracle, USA CapGemini, UK Tavant, USA Iona Technology, USA Yahoo, USA SAP, USA Oracle, USA IBM, USA HP, USA WSO2, Sri Lanka Unisys, USA

Additional Referees Grigoris Antoniou Andrei Arion George Athanasopoulos Michael Averstegge Donald Baker Venkat Balakrishnan Piergiorgio Bertoli Aliaksandr Birukou Lars Braubach Volha Bryl Andrzej Cichocki Francesco Colasuonno Marco Comerio Nick Cook Eugenio Di Sciascio Remco Dijkman Nicola Dragoni Christian Drumm

Cu Nguyen Duy Paul El-Khoury Rik Eshuis Reza Eslami Pascal Fenkam Eugen Freiter Keisuke Fukui GR Gangadaran Steffen Göbel Jan Goossenaerts Simone Grega Claudio Guidi Michael Harrison Martin Husemann Hiroshi Igaki Yuji Imai Sarath Indrakanti Marijke Janssen

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Organization

Rim Samia Kaabi Raman Kazhamiakin Natallia Kokash Jacek Kopecky Iryna Kozlowa Kathleen Krebs Christian P. Kunze Jens Lemcke Ching Lin Xumin Liu Roberto Lucchi Matteo Maffei Daniele Maggiore Zaki Malik Manolis Marazakis Annapaola Marconi Bogdan Marinoiu Andrea Maurino Harald Meyer Stefano Modafferi Carlos Molina-Jimenez Graham Morgan Enrico Mussi Marian Nodine Michael Pantazoglou Panayiotis Periorellis Marinella Petrocchi Christian Platzer Dimitris Plexousakis Alexander Pokahr

Stanislav Pokraev Frank Puhlmann Azzurra Ragone Claudia Raibule Claudia Raibulet Chun Ruan Yacine Sam Andreas Savva Alberto Siena Jim Smith Luca Spalazzi Alexander Stuckenholz Ioan Toma Martin Treiber Uday Kiran Tupakula Harald Vogt Michael von Riegen Jochem Vonk Jim Webber Stuart Wheater Simon Woodman Xu Yang Qi Yu Nicola Zannone Sonja Zaplata Uwe Zdun Yi Zhang Weiliang Zhao George Zheng

Table of Contents

Part 1: Research Track Full Papers Service Mediation Requirements and Method for Assessment of Service Interoperability . . . . Stanislav Pokraev, Dick Quartel, Maarten W.A. Steen, Manfred Reichert

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An Aspect-Oriented Framework for Service Adaptation . . . . . . . . . . . . . . . . Woralak Kongdenfha, R´egis Saint-Paul, Boualem Benatallah, Fabio Casati

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Automated Generation of BPEL Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . Antonio Brogi, Razvan Popescu

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Grid Services and Scheduling Division of Labor: Tools for Growing and Scaling Grids . . . . . . . . . . . . . . . . T. Freeman, K. Keahey, I. Foster, A. Rana, B. Sotomoayor, F. Wuerthwein DECO: Data Replication and Execution CO-scheduling for Utility Grids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vikas Agarwal, Gargi Dasgupta, Koustuv Dasgupta, Amit Purohit, Balaji Viswanathan Coordinated Co-allocator Model for Data Grid in Multi-sender Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R.S. Bhuvaneswaran, Yoshiaki Katayama, Naohisa Takahashi

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52

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Mobile and P2P Services Adaptive Preference Specifications for Application Sessions . . . . . . . . . . . . . Christine Julien Mobile Ad Hoc Services: Semantic Service Discovery in Mobile Ad Hoc Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Andronikos Nedos, Kulpreet Singh, Siobh´ an Clarke

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Discovering Web Services and JXTA Peer-to-Peer Services in a Unified Manner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Michael Pantazoglou, Aphrodite Tsalgatidou, George Athanasopoulos

Service Composition A Hierarchical Framework for Composing Nested Web Processes . . . . . . . . 116 Haibo Zhao, Prashant Doshi Using Dynamic Asynchronous Aggregate Search for Quality Guarantees of Multiple Web Services Compositions . . . . . . . . . . . . . . . . . . . . 129 Xuan Thang Nguyen, Ryszard Kowalczyk, Jun Han Service Composition (re)Binding Driven by Application–Specific QoS . . . . 141 Gerardo Canfora, Massimiliano Di Penta, Raffaele Esposito, Francesco Perfetto, Maria Luisa Villani Design of Quality-Based Composite Web Services . . . . . . . . . . . . . . . . . . . . . . 153 F. De Paoli, G. Lulli, A. Maurino

Adaptive Services AMPol-Q: Adaptive Middleware Policy to Support QoS . . . . . . . . . . . . . . . . 165 Raja Afandi, Jianqing Zhang, Carl A. Gunter Adaptive Web Processes Using Value of Changed Information . . . . . . . . . . 179 John Harney, Prashant Doshi SCENE: A Service Composition Execution Environment Supporting Dynamic Changes Disciplined Through Rules . . . . . . . . . . . . . . . . . . . . . . . . . 191 Massimiliano Colombo, Elisabetta Di Nitto, Marco Mauri A Self-healing Web Server Using Differentiated Services . . . . . . . . . . . . . . . . 203 Henri Naccache, Gerald C. Gannod, Kevin A. Gary

Data Intensive Services Quality of Service Enabled Database Applications . . . . . . . . . . . . . . . . . . . . . 215 S. Krompass, D. Gmach, A. Scholz, S. Seltzsam, A. Kemper A Model-Based Framework for Developing and Deploying Data Aggregation Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 Ramakrishna Soma, Amol Bakshi, V.K. Prasanna, Will Da Sie

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Service Management: Registry, Reliability A Distributed Approach for the Federation of Heterogeneous Registries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 Luciano Baresi, Matteo Miraz I-Queue: Smart Queues for Service Management . . . . . . . . . . . . . . . . . . . . . . 252 Mohamed S. Mansour, Karsten Schwan, Sameh Abdelaziz

XML Processing Optimizing Differential XML Processing by Leveraging Schema and Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Toyotaro Suzumura, Satoshi Makino, Naohiko Uramoto Optimized Web Services Security Performance with Differential Parsing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 Masayoshi Teraguchi, Satoshi Makino, Ken Ueno, Hyen-Vui Chung Web Browsers as Service-Oriented Clients Integrated with Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 Hisashi Miyashita, Tatsuya Ishihara

Service Modeling Interaction Soundness for Service Orchestrations . . . . . . . . . . . . . . . . . . . . . . 302 Frank Puhlmann, Mathias Weske Modeling Web Services by Iterative Reformulation of Functional and Non-functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Jyotishman Pathak, Samik Basu, Vasant Honavar SOCK: A Calculus for Service Oriented Computing . . . . . . . . . . . . . . . . . . . . 327 Claudio Guidi, Roberto Lucchi, Roberto Gorrieri, Nadia Busi, Gianluigi Zavattaro A Priori Conformance Verification for Guaranteeing Interoperability in Open Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 Matteo Baldoni, Cristina Baroglio, Alberto Martelli, Viviana Patti

Business Services: Transaction, Licensing and SLA Assessment A Business-Aware Web Services Transaction Model . . . . . . . . . . . . . . . . . . . 352 Mike P. Papazoglou, Benedikt Kratz

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Licensing Services: Formal Analysis and Implementation . . . . . . . . . . . . . . . 365 G.R. Gangadharan, Vincenzo D’Andrea QoS Assessment of Providers with Complex Behaviours: An Expectation-Based Approach with Confidence . . . . . . . . . . . . . . . . . . . . . 378 Gareth Shercliff, Jianhua Shao, W. Alex Gray, Nick J. Fiddian

Service Discovery and Selection A QoS-Aware Selection Model for Semantic Web Services . . . . . . . . . . . . . . 390 Xia Wang, Tomas Vitvar, Mick Kerrigan, Ioan Toma UML-Based Service Discovery Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 Andrea Zisman, George Spanoudakis BPEL-Unit: JUnit for BPEL Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 Zhong Jie Li, Wei Sun

Part 2: Research Track Short Papers Quality of Service (Policy, Transaction and Monitoring) A User Driven Policy Selection Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 Mariagrazia Fugini, Pierluigi Plebani, Filippo Ramoni Abstract Transaction Construct: Building a Transaction Framework for Contract-Driven, Service-Oriented Business Processes . . . . . . . . . . . . . . 434 Ting Wang, Paul Grefen, Jochem Vonk Securing Web Service Compositions: Formalizing Authorization Policies Using Event Calculus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440 Mohsen Rouached, Claude Godart Supporting QoS Monitoring in Virtual Organisations . . . . . . . . . . . . . . . . . . 447 Patrick J. Stockreisser, Jianhua Shao, W. Alex Gray, Nick J. Fiddian

Business Service Modeling Event Based Service Coordination over Dynamic and Heterogeneous Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 Gianluigi Ferrari, Roberto Guanciale, Daniele Strollo

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Implicit vs. Explicit Data-Flow Requirements in Web Service Composition Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 Annapaola Marconi, Marco Pistore, Paolo Traverso Light-Weight Semantic Service Annotations Through Tagging . . . . . . . . . . 465 Harald Meyer, Mathias Weske Service-Oriented Model-Driven Development: Filling the Extra-Functional Property Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471 Guadalupe Ortiz, Juan Hern´ andez WSMX: A Semantic Service Oriented Middleware for B2B Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477 Thomas Haselwanter, Paavo Kotinurmi, Matthew Moran, Tomas Vitvar, Maciej Zaremba Top Down Versus Bottom Up in Service-Oriented Integration: An MDA-Based Solution for Minimizing Technology Coupling . . . . . . . . . . 484 Theo Dirk Meijler, Gert Kruithof, Nick van Beest

Service Assembly Semantic Service Mediation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 Liangzhao Zeng, Boualem Benatallah, Guo Tong Xie, Hui Lei Examining Usage Protocols for Service Discovery . . . . . . . . . . . . . . . . . . . . . 496 Rimon Mikhaiel, Eleni Stroulia Sliver: A BPEL Workflow Process Execution Engine for Mobile Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 Gregory Hackmann, Mart Haitjema, Christopher Gill, Gruia-Catalin Roman Automated Discovery of Compositions of Services Described with Separate Ontologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 Antonio Brogi, Sara Corfini, Jos´e F. Aldana, Ismael Navas Dynamic Web Service Selection and Composition: An Approach Based on Agent Dialogues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 Yasmine Charif-Djebbar, Nicolas Sabouret Leveraging Web Services Discovery with Customizable Hybrid Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 Natallia Kokash, Willem-Jan van den Heuvel, Vincenzo D’Andrea

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Part 3: Industrial Track Vision and Full Papers Vision Papers Assembly of Business Systems Using Service Component Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 Anish Karmarkar, Mike Edwards The End of Business as Usual: Service-Oriented Business Transformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540 Andy Mulholland

Experience with Deployed SOA A Service Oriented Reflective Wireless Middleware . . . . . . . . . . . . . . . . . . . . 545 Bora Yurday, Halˆ uk G¨ um¨ u¸skaya Procedures of Integration of Fragmented Data in a P2P Data Grid Virtual Repository . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557 Kamil Kuliberda, Jacek Wislicki, Tomasz Kowalski, Radoslaw Adamus, Krzysztof Kaczmarski, Kazimierz Subieta Towards Facilitating Development of SOA Application with Design Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569 Wei Zhao, Ying Liu, Jun Zhu, Hui Su

SOA Architectures Dynamic Service Oriented Architectures Through Semantic Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 581 Suzette Stoutenburg, Leo Obrst, Deborah Nichols, Ken Samuel, Paul Franklin A Service Oriented Architecture Supporting Data Interoperability for Payments Card Processing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591 Joseph M. Bugajski, Robert L. Grossman, Steve Vejcik Services-Oriented Computing in a Ubiquitous Computing Platform . . . . . . 601 Ji Hyun Kim, Won Il Lee, Jonathan Munson, Young Ju Tak

Early Adoption of SOA Technology SCA Policy Association Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613 Michael Beisiegel, Nickolas Kavantzas, Ashok Malhotra, Greg Pavlik, Chris Sharp

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A Model-Driven Development Approach to Creating Service-Oriented Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624 Simon K. Johnson, Alan W. Brown Towards Adaptive Management of QoS-Aware Service Compositions – Functional Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637 Mariusz Momotko, Michal Gajewski, Andr´e Ludwig, Ryszard Kowalczyk, Marek Kowalkiewicz, Jian Ying Zhang Author Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651

Requirements and Method for Assessment of Service Interoperability Stanislav Pokraev1, Dick Quartel2, Maarten W.A. Steen1, and Manfred Reichert2 1

Telematica Instituut, The Netherlands, P.O. Box 589 7500 AN Enschede, The Netherlands Centre for Telematics and Information Technology, 2 University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands [email protected], [email protected], [email protected], [email protected]

Abstract. Service interoperability is a major obstacle in realizing the SOA vision. Interoperability is the capability of multiple, autonomous and heterogeneous systems to use each other’s services effectively. It is about the meaningful sharing of functionality and information that leads to the achievement of a common goal. In this paper we systematically explain what interoperability means and analyze possible interoperability problems. Further, we define requirements for service interoperability and present a method to assess whether a composite system meets the identified requirements. Keywords: service modeling, service interoperability, formal verification.

1 Introduction The integration of software systems is a major challenge for companies today. Both organizational forces, such as business process integration (BPI), and technology drivers, such as the move towards service-oriented architectures (SOA), put increasing pressure on software engineers to reuse and integrate existing system services, rather than building new systems from scratch. However, the lack of interoperability forms a major stumbling block in the integration process. To address this issue a lot of efforts are currently being invested in standardizing service description languages and protocols for service interactions such as WSDL, BPEL, WS-CDL. Unfortunately, these efforts mainly address what we call syntactic interoperability, whereas semantic interoperability is just starting to be addressed by initiatives such as the SWSI1 and the WSMO2 working groups. In this paper we analyze what it means for software systems to be interoperable. Based on the results of this analysis we identify possible interoperability problems and define requirements for appropriate solutions. Next, we propose a conceptual framework for service modeling as well as a method for formally verifying the interoperability of an integrated system, starting with an integration goal. The latter 1 2

http://www.swsi.org/ http://www.wsmo.org/

A. Dan and W. Lamersdorf (Eds.): ICSOC 2006, LNCS 4294, pp. 1 – 14, 2006. © Springer-Verlag Berlin Heidelberg 2006

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qualification becomes necessary because a composite system has properties that emerge due to the interaction of its components. Assessing interoperability of such a system means that one can check if a desired goal (i.e., a number of emerging properties) can be achieved by the elements of that system in concert. The paper is organized as follows: Section 2 presents our conceptual framework for service modeling. Section 3 explains what interoperability means, analyze possible interoperability problems, and define requirements for service interoperability. Section 4 presents our method for formal verification whether a composite system meets the identified interoperability requirements. Section 5 gives an overview of the state-of-the art and the related work. Finally, Section 6 presents our conclusions and discusses some future research directions.

2 A Conceptual Framework for Service Modeling This section presents our conceptual framework for service modeling. The framework defines concepts and a notation to model interactions between systems from a communication, behavioral and information perspective. The presented concepts are generic in that they can be applied in different application domains and at successive abstraction levels. This helps limiting the number of required concepts. The core concept in our framework is the interaction concept. It supports a constraint-oriented style of service specification, which facilitates the addressing of interoperability requirements by modeling the participation of interacting entities as separate constraints and by reasoning about satisfiability of the logical conjunction of these constraints. The conceptual framework is based on earlier work [12][13]. The communication perspective is concerned with modeling the interacting systems and their interconnection structure. For that purpose we introduce two basic concepts, namely Entity and Interaction point. An Entity models the existence of some system, while abstracting from its properties. An Interaction point models the existence of some mechanism that enables interaction between two or more systems, while abstracting from the properties of the mechanism. In general, the interaction mechanism is identified by its location (e.g., the combination of an IP address and port number can be used to identify a TCP/UDP socket). We adopt Webster’s definition of a system, which defines a system as “a regularly interacting or interdependent group of items, components or parts, forming a unified whole”. This definition distinguishes between two system perspectives: an internal perspective, i.e., the “regularly interacting or interdependent group of items, components or parts”, and an external perspective, i.e., the “unified whole”. Fig. 1 illustrates both perspectives. From an external perspective a system is modeled as a single entity (e.g., System A) having one or more interaction points (e.g., IP1, IP2 and IP3). From an internal perspective a system is modeled as a structure of interconnected system parts (e.g., Systems A1, System A2 and System A3). The behavioral perspective is concerned with modeling the behavioral properties of a system, i.e., the activities that are performed by the system as well as the relations among them. For that purpose we introduce four basic concepts, namely, Action, Interaction, Interaction contribution and one relation, namely, Causality relation.

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Interaction point

Entity

IP IP11

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IP IP11 System System AA11

… …

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External system perspective (…forming unified whole)

IP IP22

… … A

IP IP33

System System AA22

System System AA33 IP IP33

Internal system perspective (… interacting or interdependent group of items, components, or parts…)

Fig. 1. Communication perspective

An Action represents a unit of activity that either occurs (completes) or does not occur (complete) during the execution of a system. Furthermore, an action only represents the activity result (effect) that is established upon completion, and abstracts from the way this result is achieved. An Interaction represents a common activity of two or more entities. An interaction can be considered as a refinement of an action, defining the contribution of each entity involved in the interaction. Therefore, an interaction inherits the properties of an action. In addition, an interaction either occurs for all entities that are involved, or does not occur for any of them. In case an interaction occurs, the same result is established for all involved entities. An Interaction contribution represents the participation (or responsibility) of an entity that is involved in an interaction. An interaction can only occur if each involved entity can participate. An entity can participate if the causality condition of its interaction contribution is satisfied (see below). In addition, an interaction contribution may define constraints on the possible results that can be established in the interaction. This means that an interaction represents a negotiation among the involved entities, only defining the potential results of the interaction, while abstracting from how they are established. We distinguish three basic types of negotiation between two entities A and B. • • •

Value checking: entity A proposes a single value x as interaction result and entity B proposes a single value y. The interaction can only occur if x = y, in which case the interaction result is x; Value passing: entity A proposes a single value x as interaction result and entity B accepts a set of values Y. The interaction can only occur if x ∈ Y, in which case the interaction result is x; Value generation: entity A accepts a set of values X as interaction result and entity B accepts a set of values Y. The interaction can only occur if X ∩ Y ≠∅, in which case the interaction result is a value from the intersection of X and Y (while abstracting from the choice of the particular value).

For an action or interaction contribution, say a, a Causality relation defines the condition that must be satisfied to enable the occurrence of a. Three basic conditions are distinguished:

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Enabling condition b, which defines that a depends on the occurrence of b, i.e., b must have occurred before a can occur; Disabling condition ¬b, which defines that a depends on the non-occurrence of b, i.e., b must not have occurred before nor simultaneously with a to allow for the occurrence of a; Start condition √, which defines that a is allowed to occur from the beginning of the behavior, independent of any other actions or interaction contributions. Composite system

Refinement

Buy

Ship

Composite system Buyer

Seller Buy

behavior

action

Buy

Shipper Ship

interaction

Ship

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enabling condition

Fig. 2. Refinement of an action

The behavioral concepts are illustrated in Fig. 2. At the higher abstraction level action Buy is followed by action Ship. At the lower level the actions are refined by assigning actors (e.g., Buyer, Seller and Shipper) that contribute to the result of these actions. Constraints on the results of interactions that systems may define are discussed later after having introduced the information perspective. Basic conditions can be combined to represent more complex causality conditions. For this we provide the AND and the OR operators, which define that a conjunction and disjunction of conditions must be satisfied, respectively. The information perspective is concerned with modeling the subject domain of a system. First, we explain what subject domain is and then we introduce five basic modeling concepts. Software systems manage a domain of lexical items. These items represent entities and phenomena in the real world that are identifiable by the system (e.g., people, companies or locations). In this context we denote the part of the world that is identifiable by the systems as subject domain of the system. Software systems interact with their environment by exchanging messages. Messages that enter the system request or update the state of its lexical domain. Messages that leave the system request information about the system’s subject domain or provide information about the lexical domain of the system. Messages consist of data that represent property values of entities or phenomena from the subject domain. The data in the messages have meaning only when interpreted in terms of the subject domain model of the system. To model the information perspective we provide five basic concepts, namely Individual, Class, Property, Result constraint and Causality constraint.

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An Individual represents an entity or phenomenon in the subject domain of the system, e.g., the person “John”, the hospital “Saint Joseph” or the city “London”. A Class represents an abstract type of entities or phenomena in the subject domain of the system, e.g., “Patient”, “Hospital” or “City”. A Property represent possible relations that can exist between entities or phenomena in the system’s subject domain, e.g., “admitted to”, “is a” or “is located in”. A Result constraint models a condition on the result of an action or interaction contribution that must be satisfied after the occurrence of the action or interaction contribution. A Causality constraint models a condition on the results established in causal predecessors (i.e., actions or interaction contributions) that must be satisfied to enable the occurrence of an action or interaction contribution. Fig. 3 shows how information concepts are related to interactions. Result constraint

Class

Patient ?p Appointment ?a ?a startTime ?t [ ?t ≤ 10pm ]

Patient ?p Appointment ?a ?a startTime ?t ?a duration ?d [?d ≤ 1h ] Property

Individual

drSmith freeSlots ?s [ ?s > 0 ] Causality constraint

Fig. 3. Relating information concepts to an interaction

In the example a system requests an appointment for a patient starting not later than 10pm. The hospital system accepts any appointments with duration less or equal than 1 hour. In addition, the interaction can only happen if Dr. Smith (the healthcare professional responsible for this case) has free slots in his calendar. Indeed, this is a causality constraint if the individual drSmith has been established as a result of a preceding (inter)action. We use Description Logics (DL)[6], more specifically OWL-DL[7] to represent our information concepts by a concrete formalism. DL ontologies consist of concepts, roles and individuals. Individuals represent entities of phenomena from the real world, concepts represent abstract classes of entities or phenomena, and roles represent relations between entities or phenomena. A concept can be atomic, i.e., denoted by its name (e.g., Patient, Room or Hospital) or defined as an expression that contains other concepts, roles and composition operators such as union or intersection. Besides concepts, individuals and relations, DL ontologies consist of a set of axioms specifying the properties of the concepts, roles and individuals. Examples of such axioms are concept inclusion (C(x) ∧ C ⊆ D → D(x)), role inclusion

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(R(x, y) ∧ R ⊆ S → S(x, y)), transitive role (R(x, y) ∧ R(y, z) → R(x, z)), etc. For the formal semantics of OWL-DL we refer to [7]. Putting together the three modeling perspectives yields an integrated service model. A service is a set of related interactions between the system and its environment. An example is given in Fig. 4a. It shows two interacting behaviors, representing the behaviors the one of a system and another one of its environment. These entities can engage in three interactions a, b and c, which are related by causality relations. The interaction contributions can be adorned with result constraints and the causality relations with causality constraints respectively. Taken together, the interactions, their causal relations and the information constraints define the service between the system and the environment. Our definition of service does not include a sense of direction. It is an interaction that models a common activity of two or more entities in which some results (values) can be established, but abstracts from who takes the initiative or the direction in which values flow. However, often it is useful to talk about the service that is offered by a system without having to specify the constraints of the environment. Likewise, it is also often useful to talk about the service that is requested by an entity without making assumptions about the constraints of the service provider. These are two complementary views on a service, which can be obtained by only specifying one entity’s contributions and constraints (cf. Fig. 4b and Fig. 4c). System

a

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b

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Requested Service

Environment

a)

b)

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Assumptions c)

Fig. 4. Service model

3 Requirements for Interoperability In our approach we distinguish three different levels of interoperability, namely syntactic, semantic and pragmatic. Syntactic interoperability is concerned with ensuring that data from the exchanged messages are in compatible formats. The message sender encodes data in a message

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using syntactic rules, specified in some grammar. The message receiver decodes the received message using syntactic rules defined in the same or some other grammar. Syntactic interoperability problems arise when the sender’s encoding rules are incompatible with the receiver’s decoding rules, which leads to (construction of) mismatching message parse trees. Web Services standards address syntactic interoperability by providing XMLbased standards such as SOAP, WSDL and BPEL. XML is a platform-independent markup language capable of describing both data and data structure. This way, different systems can parse each other’s messages, check if these messages are wellformed, and validate if the messages adhere to a specific syntactic schema. In our approach we adopt XML to deal with syntactic interoperability and only focus on semantic and pragmatic interoperability. Semantic interoperability is concerned with ensuring that the exchanged information has the same meaning for both message sender and receiver. The data in the messages have meaning only when interpreted in terms of the respective subject domain models. However, the message sender does not always know the subject domain model of the message receiver. Depending on its knowledge, the message sender makes assumptions about the subject domain model of the receiver and uses this assumed subject domain model to construct a message and to communicate it. Semantic interoperability problems arise when the message sender and receiver have a different conceptualization or use a different representation of the entity types, properties and values from their subject domains. Examples of such differences are naming conflicts (same representation is used to designate different entities, entity types or properties, or different representations are used to designate the same entity, entity type or property), generalization conflicts (the meaning of an entity type or a property is more general than the meaning of the corresponding entity type or property), aggregation conflicts (an entity type aggregates two or more corresponding entity types), overlapping conflicts (an entity type or a property partially overlaps a corresponding entity type or a property), isomorphism conflicts (the same entity type or property is defined differently in different subject domain models), identification conflicts (the same entity is identified by different properties), entity-property conflicts (an entity type in modeled as a property), etc. To address the identified semantic conflicts we define the following requirement: Requirement 1: A necessary condition for the semantic interoperability of two systems is the existence of a translation function that maps the entity types, properties and values of the subject domain model of the first system to the respective entity types, properties and values of the subject domain model of the second system. Pragmatic interoperability is concerned with ensuring that message sender and receiver share the same expectation about the effect of the exchanged messages. When a system receives a messages it changes its state, sends a message back to the environment, or both[18]. In most cases, messages sent to the system change or request the system state, and messages sent from the system change or request the state of the environment. That is, the messages are always sent with some intention for achieving some desired effect. In most of the cases the effect is realized not only

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by a single message but by a number of messages send in some order. Pragmatic interoperability problems arise when the intended effect differs from the actual effect. Requirement 2: A necessary condition for pragmatic interoperability of a single interaction is that at least one result that satisfies the constraints of all contributing systems can be established. As said earlier, a service is a set of related interactions between the system and its environment. Requirement 3: A necessary condition for pragmatic interoperability of a service is that Requirement 2 is met for all of its interactions and they can occur in a causal order, allowed by all participating systems. The requirements are discussed in more details in the next section.

4 Formal Verification of Service Designs In this section we present a formal method for checking if a service design meets the requirements identified in the previous section. To address Requirement 1 we need a method to establish mappings between values, concepts and relations from subject domains of the systems being integrated. This method requires understanding of the meaning of values, concepts and relations from the respective subject domains and cannot be fully automated. However, tools exist that use sophisticated heuristic algorithms to discover possible mappings and provide mechanisms for specifying these mappings. Besides mapping there are two other relevant approaches: alignment and merging of the subject domain models. Alignment is the process of making the subject domain models consistent and coherent with one another while keeping them separate. Merging is the process of creating a single subject domain model that includes the information from all source subject domain models. To address the semantic conflicts identified in the previous section we need a formal language capable of expressing mappings. In the following we show how some of the identified problems can be addressed using OWL-DL axioms. In the explanation below we use the prefixes a: and b: to identify a concept or a relation in the subject domain model of System A and System B respectively. Naming conflicts can be addressed using axioms that assert sameness (e.g., a:Medicine ≡ b:Drug) or difference (a:Employee ≠ b:Employee). Aggregation conflicts can be addressed using axioms that define a new concept as aggregation of the corresponding concepts (e.g., a:Address ≡ List (b:StreetNo, b:Street, b:City). Generalization conflicts can be addressed using axioms that assert the generalization (or specialization) relation between the respective concepts (a:Human ⊆ b:Patient). Overlapping conflicts can be addressed using axioms that assert that corresponding concepts are not disjoint (e.g., ¬(a:Man ∩ b:Adult) ⊆ ⊥ ). Unfortunately, not all types of mappings can be expressed using OWL. For example, OWL does not allow for property chaining (e.g., a:hasUncle ≡ b:hasBrother • b:hasFather) and qualified cardinality restrictions

Requirements and Method for Assessment of Service Interoperability a:SafeBuilding

=

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b:Building ∩ ≥2b:hasStairs.b:FireEscapeStairs

which makes it difficult (in some cases impossible) to deal with isomorphic and cardinality conflicts. However, some of these issues are being dealt with in the upcoming version of OWL 1.1. To address Requirement 2 we define a class as an intersection of the classes that define the admissible results of an interaction for all participating interaction contributions, and check if the concept that represents the class is satisfiable. As said earlier, we use OWL-DL as a representation system for individuals, classes and properties as well as to define result and causality constraints. This way, we can describe the subject domains of the system, define classes that represent the conditions and results of actions and interaction contributions and reason if these classes can have instances or not. The basic reasoning task in OWL-DL is subsumption check – a task of checking if a concept D is more general than a concept C. In other words, subsumption is checking if the criteria for being individual of type C imply the criteria for being individual of type D. The concept D is called subsumer and the concept C is called subsumee. If C subsumes D and D subsumes C, then we can conclude that class C and D are equivalent. Checking concept satisfiability is a special case of subsumption reasoning. In this case the subsumer is the empty concept (⊥). If a concept C is subsumed by the empty concept we say that the concept C is not satisfiable. This means that no individual can be of type C. Requirement 2 is illustrated in Fig. 5. In this example, any appointment not earlier than 10pm with duration no longer that 1 hour is a possible result of the interaction a. Patient p Time t Duration d

Patient p Time t Duration d

[t

[d

≥ 10pm ]

≤ 1h ]

Healthcare Professional

Hospital Healthcare professional

a

a

Hospital Information System

Possible results of the interaction Any patient, time not before 10pm and duration no longer than 1 hour

Fig. 5. Example of Requirement 2

To check if a composite system meets Requirement 3 we translate a model of a composite service described in our language to a Coloured Petri Net (CPN)[8][9]. This way we can construct the corresponding occurrence graph and reason about the dynamic properties of the model. The presented mapping is partially based on previous work [16]. A classical Petri Net (PN) consists of a set of places (represented by circles), a set of transitions (represented by black bars), directed arcs connecting places to transitions or transitions to places, and markings assigning one or more tokens (represented by black dots) to some places. CPNs extend the classical PNs by providing a mechanism for associating a value of a certain type to each token. In

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addition, a transition can be enabled only if its input tokens satisfy certain conditions (guards) and produce output tokens that represent new values (bindings). In this way, a transition can be seen as a function that maps input values to output values in a certain context. An action in our language maps to a transition in terms of PNs. A transition can be executed when all incoming places contain at least one token. On execution it consumes a token from all incoming places and produces a token in all outgoing places. Similar to actions, enabled transitions may execute in parallel. Nets that correspond to some elementary causality relations from our language are depicted in Fig. 6: √

a

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b a b ∧ c (AND-Split)

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a c a ∧ b (AND-join) a

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a b ∨ c (OR-Split)

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Fig. 6. Mapping to Petri Nets

As said earlier, the occurrence or the result of an action (or interaction) may depend on the result of one or more causal predecessors (actions or interactions). Such dependences can be easily mapped onto guards and bindings in terms of CPNs. Fig. 7 shows an example of the respective mappings. The occurrence of action a depends on the results of actions b and c int x

b x

b a

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c int y

y

x

a

y [x+y