Modern Business Process Automation Arthur H

Modern Business Process Automation Arthur H. M. ter Hofstede • WilM.P.vanderAalst Michael Adams • Nick Russell

Editors

Modern Business Process Automation

YAWL and its Support Environment

123 Editors Arthur H. M. ter Hofstede Michael Adams Queensland University of Queensland University of Technology Technology School of Information Systems School of Information Systems Fac. Information Technology Fac. Information Technology GPO Box 2434, level 5, GPO Box 2434, level 5, 126 Margaret Street, 126 Margaret Street, Brisbane QLD 4001 Brisbane QLD 4001 Australia Australia [email protected] [email protected]

WilM.P.vanderAalst Nick Russell Eindhoven University of Eindhoven University of Technology Technology Dept. Mathematics & Fac. Technology Management Computer Science Den Dolech 2 Den Dolech 2 5600 MB Eindhoven 5600 MB Eindhoven Netherlands Netherlands [email protected] [email protected]

ISBN 978-3-642-03120-5 e-ISBN 978-3-642-03121-2 DOI 10.1007/978-3-642-03121-2 Springer Heidelberg Dordrecht London New York

Library of Congress Control Number: 2009931714

ACM Computing Classiﬁcation (1998): J.1, H.4

c Springer-Verlag Berlin Heidelberg 2010 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

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Springer is part of Springer Science+Business Media (www.springer.com) Preface

The field of Business Process Management (BPM) is marred by a seemingly end- less sequence of (proposed) industry standards. Contrary to other fields (e.g., civil or electronic engineering), these standards are not the result of a widely supported consolidation of well-understood and well-established concepts and practices. In the BPM domain, it is frequently the case that BPM vendors opportunistically become involved in the creation of proposed standards to exert or maintain their influence and interests in the field. Despite the initial fervor associated with such standardization activities, it is no less frequent that vendors either choose to drop their support for standards that they earlier championed on an opportunistic basis or elect only to partially support them in their commercial offerings. Moreover, the results of the standardization processes themselves are a concern. BPM standards tend to deal with complex concepts, yet they are never properly defined and all-too-often not informed by established research. The result is a plethora of languages and tools, with no consensus on concepts and their implementation. They also fail to provide clear direction in the way in which BPM standards should evolve. One can also observe a dichotomy between the “business” side of BPM and its “technical” side. While it is clear that the application of BPM will fail if not placed in a proper business context, it is equally clear that its application will go nowhere if it remains merely a motivational exercise with schemas of business processes hanging on the wall gathering dust. An important observation that can be made about the state-of-the-art in BPM relates to tool support. Tool support has evolved considerably in the past decade, both in terms of the breadth of functionality that is provided and in terms of the range and capabilities of the vendors who are involved. However, because of the lack of effective standardization and direction in the field, BPM technology is not widely used. Commercial BPM tools are rarely used in small and medium-sized enterprises because of their prohibitive total cost of ownership. Acquisition costs tend to be high, and ongoing operational support and maintenance commitments can be even higher. One factor in this is that the closed nature of these products means that their customization to specific client requirements may be difficult or even impossible to achieve, and only the biggest users may be able to influence their future feature set. Another issue is the scarcity of knowledge about individual

v vi Preface

BPM offerings and the fact that product knowledge does not generalize. This means that it remains difficult for end users to really leverage the capabilities of their BPM investment. So where does this leave those interested in the field of BPM? First, it is unwise to become too aligned with or invest too heavily in particular standards, tools, or technologies. These all come and go. It is imperative that the conceptual, formal, and technological foundations of BPM are thoroughly understood. Only this way can one survive the onslaught of “the latest and greatest” in BPM and not have the wool pulled over one’s eyes by vendors, training organizations, and other interested parties. Second, it is important to not only develop an understanding of the business context of BPM and its main drivers but also of the fundamentals of business process automation. To automate processes, it is vital to have a correct understanding of the operation of the business processes. This can be obtained by process mining and advanced simulation techniques. Measurable benefits can be realized by business process automation if the right set of patterns is supported. Finally, the (increased) uptake of Linux and other open-source products in the past decade has provided real momentum for the open-source movement. This has also influenced the BPM land- scape, and where once there was no alternative to commercial, closed-source, and expensive solutions, such alternatives have now become viable in many instances. The markedly lower acquisition costs and the ability to modify the software to suit one’s own needs cannot be ignored as factors in software selection processes and make the use of BPM technology an attractive proposition for a much wider range of potential users, including those in small and medium-sized enterprises for whom it was previously cost-prohibitive. The book in front of you is the culmination of more than ten years of research and development conducted at universities in different parts of the world. It aims to provide the reader with a deep insight into fundamental concepts and techniques that are core to understanding BPM and its application. The focus is not on business/motivational aspects, though these aspects are not ignored. The book is primarily intended as a textbook for undergraduate and postgrad- uate students in the field of workflow, or BPM more broadly. However, it is also eminently suitable as a reference for BPM researchers and professionals as it cov- ers a wide range of BPM-related topics in a highly accessible yet thorough way. Exercises to deepen the reader’s knowledge are provided throughout and the chap- ter notes at the end of many chapters provide the reader with references to further work in the area. The book uses YAWL (Yet Another Workflow Language), a powerful language based on the well-known workflow patterns, and its open-source support environment, to explain advanced concepts and their realization. This book is an edited work and would not have been possible without the contributions of a wide range of experts in the field. They take the reader through the fundamentals of business process modeling and automation, various aspects of flexibility, a number of current industry standards, and advanced topics such as integration, verification, mining, and configuration. In addition, implementation aspects relevant to modern BPM environments are addressed in depth and applications of BPM in the domains of health and screen business are discussed. Preface vii

We feel privileged to have worked with many enthusiastic, committed, and knowledgeable people over the years. In addition to the authors of the various chapters in this book, we wish to thank the following people for their contributions to the YAWL initiative: Lindsay Bradford, Carmen Bratosin, Ross Brown, Francesco Cardi, Evan Chen, David Edmond, Tore Fjellheim, Matt Flaherty, Mike Fowler, Andrew Hastie, Saphira Heijens, Sean Kneipp, Jan-Christian Kuhr, Giancarlo La Medica, Massimiliano de Leoni, Alfredo Nantes, Ignatius Ong, Helen Paik, Jessica Prestedge, Guy Redding, Dan Simkins, Alex Streit, David Truffet, S«ebastien Vicente, and Kenneth Wang. We also gratefully acknowledge support from the Australian Research Coun- cil, the ARC Centre of Excellence for Creative Industries and Innovation, and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO). We sincerely hope that this book provides a valuable resource to the reader in the years to come.

Brisbane, Australia Arthur ter Hofstede Eindhoven, the Netherlands Wil van der Aalst Brisbane, Australia Michael Adams Eindhoven, the Netherlands Nick Russell Contents

Part I Introduction

1 Introduction ...... 3 Wil van der Aalst, Michael Adams, Arthur ter Hofstede, and Nick Russell 1.1 Overview...... 3 1.2 OntheRoleofModelsinBPM ...... 5 1.3 BPMStandardApproaches...... 7 1.4 The Workﬂow Patterns Initiative ...... 8 1.5 PetriNetsandWorkﬂowNets...... 10 1.6 TheEmergenceofYAWL...... 10 1.7 A BriefOverviewofYAWL...... 11 1.8 PositioningofYAWL...... 14 1.9 OverviewoftheBook ...... 16

Part II Concepts

2 The Language: Rationale and Fundamentals ...... 23 Nick Russell and Arthur ter Hofstede 2.1 Introduction ...... 23 2.2 WorkﬂowPatterns ...... 25 2.3 Formal Foundation ...... 50 2.4 Control-ﬂow...... 57 2.5 Data...... 64 2.6 Resources...... 71 2.7 Syntax ...... 87 2.8 WorkingExample...... 92 2.9 Conclusion ...... 97

3 Advanced Synchronization ...... 103 Moe Wynn, Wil van der Aalst, and Arthur ter Hofstede 3.1 Introduction ...... 103 3.2 TheOR-JoinSemantics...... 104

ix x Contents

3.3 Motivation...... 108 3.4 OperationalizingtheOR-Join ...... 112 3.5 Conclusion ...... 116

Part III Flexibility and Change

4 Dynamic Workﬂow ...... 123 Michael Adams 4.1 Introduction ...... 123 4.2 YAWLandDynamicWorkﬂow...... 124 4.3 Worklets:TheoreticalBasis ...... 125 4.4 ConceptualizationofWorklets ...... 128 4.5 Context,Rules,andWorkletSelection...... 129 4.6 TheSelectionProcess...... 134 4.7 ServiceInterface...... 136 4.8 Secondary Data Sources ...... 139 4.9 Conclusion ...... 140

5 Exception Handling ...... 147 Michael Adams and Nick Russell 5.1 Overview...... 147 5.2 A GeneralFrameworkforExceptionHandling ...... 148 5.3 YAWLeX: A Graphical Exception Handling Language ...... 154 5.4 ExceptionHandlinginYAWL ...... 158 5.5 Epilogue ...... 170

6 Declarative Workflow ...... 175 Maja Pesic, Helen Schonenberg, and Wil van der Aalst 6.1 Introduction ...... 175 6.2 Constraint-basedWorkflowSpecification ...... 179 6.3 EnactmentofConstraintModelInstances...... 190 6.4 DynamicInstanceChange...... 194 6.5 Conclusions ...... 196

Part IV The Core System

7 The Architecture...... 205 Michael Adams, Marlon Dumas, and Marcello La Rosa 7.1 ArchitecturalandImplementationConsiderations...... 205 7.2 A Three-TierViewoftheYAWLSystem...... 206 7.3 YAWL Services and Interfaces ...... 209 7.4 Summary ...... 218 Contents xi

8 The Design Environment ...... 221 Stephan Clemens, Marcello La Rosa, and Arthur ter Hofstede 8.1 Introduction ...... 221 8.2 Setting up the Process Control Logic ...... 222 8.3 DeﬁningDataAspects...... 227 8.4 AssigningHumanResourcestotheProcess...... 231 8.5 ErrorReporting ...... 234 8.6 SpeciﬁcationFile ...... 236 8.7 Summary ...... 238

9 The Runtime Environment ...... 241 Michael Adams 9.1 Introduction ...... 241 9.2 BasicOperations...... 241 9.3 InternalArchitecture...... 243 9.4 TheLife-Cycleofa Case...... 246 9.5 TheLife-Cycleofa Workitem...... 249 9.6 Persistence...... 252 9.7 Logging...... 254 9.8 Summary ...... 257

Part V Services

10 The Resource Service...... 261 Michael Adams 10.1 Introduction ...... 261 10.2 FunctionalOverview...... 261 10.3 OrganizationalModel...... 265 10.4 Architecture...... 269 10.5 Initial Distribution ...... 278 10.6 Privileges...... 281 10.7 TheWorklist ...... 284 10.8 Conclusion ...... 288

11 The Worklet Service ...... 291 Michael Adams 11.1 Introduction ...... 291 11.2 ServiceOverview...... 291 11.3 ServiceOrientedArchitecture...... 293 11.4 WorkletServiceArchitecture...... 295 11.5 ServiceInstallationandConfiguration...... 298 11.6 Worklet Process Definition ...... 301 11.7 Exlet Process Definition ...... 306 11.8 Ripple-DownRuleSets...... 312 11.9 ExtendingtheAvailableConditionals ...... 314 11.10 TheRulesEditor...... 315 xii Contents

12 The Declare Service ...... 327 Maja Pesic, Helen Schonenberg, and Wil van der Aalst 12.1 Introduction ...... 327 12.2 ServiceArchitecture...... 328 12.3 ConstraintTemplates ...... 330 12.4 ConstraintWorkflowModels...... 330 12.5 VerificationofConstraintModels...... 333 12.6 ExecutionofConstraintModelInstances...... 333 12.7 OptionalConstraints...... 336 12.8 DynamicInstanceChange...... 337 12.9 DecompositionsofYAWLandDeclarativeWorkflows...... 339 12.10 Conclusions ...... 341

Part VI Positioning

13 The Business Process Modeling Notation ...... 347 Gero Decker, Remco Dijkman, Marlon Dumas, and Luciano Garc«õa-Ba˜nuelos 13.1 Introduction ...... 347 13.2 BPMN ...... 348 13.3 MappingBPMNtoYAWL...... 355 13.4 Tool Support ...... 364 13.5 Summary ...... 365

14 EPCs ...... 369 Jan Mendling 14.1 Introduction ...... 369 14.2 Event-DrivenProcessChains...... 370 14.3 PatternComparisonofYAWLandEPCs...... 372 14.4 MappingEPCstoYAWL...... 373 14.5 MappingYAWLtoEPCs...... 374 14.6 TransformationbySynthesis...... 379 14.7 Conclusion ...... 381

15 The Business Process Execution Language ...... 385 Chun Ouyang, Marlon Dumas, and Petia Wohed 15.1 Introduction ...... 385 15.2 Overview of BPEL through the YAWL Prism ...... 387 15.3 Workﬂow Patterns Support ...... 394 15.4 Epilogue ...... 398

16 Open Source Workﬂow Systems ...... 401 Petia Wohed, Birger Andersson, and Paul Johannesson 16.1 Introduction ...... 401 16.2 OpenWFEru:Ruote...... 401 Contents xiii

16.3 jBPM ...... 411 16.4 Enhydra Shark ...... 422 16.5 Epilogue ...... 431

Part VII Advanced Topics

17 Process Mining and Simulation ...... 437 Moe Wynn and Anne Rozinat and Wil van der Aalst and Arthur ter Hofstede, and Colin Fidge 17.1 Introduction ...... 437 17.2 PaymentProcess...... 437 17.3 ProcessMiningandYAWL...... 438 17.4 ProcessSimulationandYAWL...... 443 17.5 Conclusion ...... 454

18 Process Configuration ...... 459 Florian Gottschalk and Marcello La Rosa 18.1 Introduction ...... 459 18.2 HowDoesProcessConfigurationWork?...... 460 18.3 ConfiguringYAWLModels...... 462 18.4 Steering Process Configuration Through Questionnaires ...... 468 18.5 ApplyingConfigurationDecisionstoYAWLModels...... 474 18.6 Tool Support ...... 480 18.7 Summary ...... 483

19 Process Integration ...... 489 Lachlan Aldred 19.1 Introduction ...... 489 19.2 CouplingDimensions...... 495 19.3 BatchMessaging...... 501 19.4 SeekingFeedback:BidirectionalInteractions...... 502 19.5 ComposedInteractions ...... 504 19.6 Event-basedProcessPatterns...... 506 19.7 Transformations...... 507 19.8 ProcessDiscovery...... 508 19.9 Conclusion ...... 509

20 Veriﬁcation ...... 513 Eric Verbeek and Moe Wynn 20.1 Introduction ...... 513 20.2 Preliminaries...... 514 20.3 Soundness of YAWL Models...... 517 20.4 Soundness-Preserving Reduction Rules ...... 521 20.5 StructuralInvariantProperties...... 533 xiv Contents

20.6 Tools...... 534 20.7 ConcludingRemarks...... 536

Part VIII Case Studies

21 YAWL4Healthcare...... 543 Ronny Mans and Wil van der Aalst and Nick Russell and Arnold Moleman and Piet Bakker, and Monique Jaspers 21.1 Introduction ...... 543 21.2 HealthcareProcesses...... 545 21.3 GynecologicalOncology ...... 547 21.4 Realization ...... 553 21.5 Conclusions ...... 561

22 YAWL4Film ...... 567 Chun Ouyang 22.1 Introduction ...... 567 22.2 Overview of Film Production Processes ...... 568 22.3 YAWL4FilmDesignandImplementation...... 570 22.4 YAWL4FilmDeployment ...... 578 22.5 Pilot Applications: Rope Burn and Family Man ...... 584 22.6 Epilogue ...... 585 Exercises ...... 585

Part IX Epilogue

23 Epilogue ...... 591 Wil van der Aalst, Michael Adams, Arthur ter Hofstede, and Nick Russell 23.1 Overview...... 591 23.2 PositioningofYAWL...... 593 23.3 Analysis ...... 594 23.4 NextSteps...... 596

Part X Appendices

A The Order Fulﬁllment Process Model ...... 599 Marcello La Rosa, Stephan Clemens, and Arthur ter Hofstede A.1 Introduction ...... 599 A.2 OverallProcess...... 599 A.3 Ordering...... 603 A.4 Carrier Appointment ...... 604 A.5 Payment ...... 607 A.6 FreightinTransit...... 608 A.7 FreightDelivered ...... 609 Contents xv

A.8 ShowcasedYAWLfeatures...... 610 A.9 Setup...... 612

B Mathematical Notation...... 613 Nick Russell

C The Original Workﬂow Patterns ...... 615 Nick Russell

References...... 617

Index ...... 635

Cited Author Index ...... 665

Acronyms ...... 671

Useful Websites ...... 675 Contributors

W.M.P. (Wil) van der Aalst Eindhoven University of Technology, Eindhoven, the Netherlands M. (Michael) Adams Queensland University of Technology, Brisbane, Australia L. (Lachlan) Aldred Queensland University of Technology, Brisbane, Australia B. (Birger) Andersson Stockholm University and The Royal Institute of Technology, Stockholm, Sweden P.J.M. (Piet) Bakker Academic Medical Center, Amsterdam, the Netherlands S. (Stephan) Clemens Queensland University of Technology, Brisbane, Australia G. (Gero) Decker University of Potsdam, Berlin, Germany R.M. (Remco) Dijkman Eindhoven University of Technology, Eindhoven, the Netherlands M. (Marlon) Dumas University of Tartu, Tartu, Estonia C.J. (Colin) Fidge Queensland University of Technology, Brisbane, Australia L. (Luciano) Garc«õa-Banuelos˜ Universidad Aut«onoma de Tlaxcala, Tlaxcala, Mexico F. (Florian) Gottschalk Eindhoven University of Technology, Eindhoven, the Netherlands A.H.M. (Arthur) ter Hofstede Queensland University of Technology, Brisbane, Australia M.W.M. (Monique) Jaspers University of Amsterdam, Amsterdam, the Netherlands P. (Paul) Johannesson Stockholm University and The Royal Institute of Technology, Stockholm, Sweden M. (Marcello) La Rosa Queensland University of Technology, Brisbane, Australia

xvii xviii Contributors

R.S. (Ronny) Mans Eindhoven University of Technology, Eindhoven, the Netherlands J. (Jan) Mendling Humboldt-Universit¬at zu Berlin, Berlin, Germany A.J. (Arnold) Moleman Academic Medical Center, Amsterdam, the Netherlands C. (Chun) Ouyang Queensland University of Technology, Brisbane, Australia M. (Maja) Pesic Eindhoven University of Technology, Eindhoven, the Netherlands A. (Anne) Rozinat Eindhoven University of Technology, Eindhoven, the Netherlands M.H. (Helen) Schonenberg Eindhoven University of Technology, Eindhoven, the Netherlands N.C. (Nick) Russell Eindhoven University of Technology, Eindhoven, the Netherlands H.M.W. (Eric) Verbeek Eindhoven University of Technology, Eindhoven, the Netherlands P. (Petia) Wohed Stockholm University and The Royal Institute of Technology, Stockholm, Sweden M.T. (Moe) Wynn Queensland University of Technology, Brisbane, Australia