Web-based collaborative workflow design [Elektronische Ressource] / vorgelegt von Markus Held

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• Informatik

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• Publié par: eberhard_karls_universitat_tubingen
• Publié le: 01 janvier 2010
• Nombre de lectures: 37
• Langue: English
• Poids de l'ouvrage: 4 Mo

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Web-based Collaborative Workflow Design









Dissertation
der Fakultät für Informations- und Kognitionswissenschaften
der Eberhard-Karls-Universität Tübingen
zur Erlangung des Grades eines
Doktors der Naturwissenschaften
(Dr. rer. nat.)






vorgelegt von
Dipl.-Inform. Markus Held
aus Balve im Sauerland



Tübingen
2010




























Tag der mündlichen Qualifikation: 07.07.2010
Dekan: Prof. Dr.-Ing. Oliver Kohlbacher
1. Berichterstatter: Prof. Dr. Wolfgang Küchlin
2. Berichterstatter: Prof. Dr. Herbert Klaeren
Dedicated to my family.
iiiAcknowledgements
As much as this thesis is about collaboration, it could not have come to existence
without the support from many people.
First, I would like to express my deep gratitude towards my advisor Prof. Dr. Wolf-
gang Ku¨chlin, and towards Dr. habil. Wolfgang Blochinger for the invaluable guid-
ance they have given to me in the course of my dissertation project.
Dr. Dierk Wanke, Dr. Kenneth Berendzen, and Prof. Dr. Klaus Harter of the Zen-
trum fu¨r Molekularbiologie der Pflanzen have given me helpful advice on contem-
porary biology and cooperated in the supervision of Moritz Werning’s diploma the-
sis. Moritz Werning has been of great influence in the course of the project. Daniel
Lehle, Stefan Raue, and Max Gu¨nther helped a lot with their undergraduate work.
Philip Effinger, Benjamin Albrecht, Stefan Kottler and Prof. Dr. Michael Kaufmann
cooperated on BPEL visualization.
Many colleagues at the Symbolic Computation Group and other groups of the
Wilhelm Schickard Institute provided me with input, new ideas, and other forms
of support. Sven Schulz supervised my own diploma thesis, leading to my first
co-authorship of a journal article. I enjoyed many philosophical debates with Eray
Genc¸ay and Julia Trieflinger, to which Matthias Sauter provided a healthy down-to-
earth attittude.
Many of my personal friends encouraged me to take up the path leading to this
dissertation. Some even encouraged me to pursue other projects in the future.
During my undergradute and graduate studies, my fraternity, the Katholische Stu-
dentenverbindung Rechberg, gave me the room to explore my own creativity, and
practice social skills and leadership. Some of my frat brothers I count among my
closest friends.
My internship at Titan Corporation was a very special influence in my career,
where Barbara and Dave Rogers provided me with outstanding hospitality and friend-
ship.
My parents Helga and Hans-Bernd Held strongly supported my dissertation project,
as did my sister Monika Tegethoff and her husband Thomas. I close these acknowl-
edgements in loving memory of my grandparents Maria and Ferdinand Held, and
Elisabeth and Helmut Neuhaus.
iiiAcknowledgements
ivContents
Acknowledgements iii
List of Tables xi
List of Figures xiii
1 Introduction 1
1.1 Introducing Workflows . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Workflows as a Means and Product of Collaboration . . . . . . . . . 2
1.3 The Case of Business Workflows . . . . . . . . . . . . . . . . . . . 3
1.4 The Case of E-Biology Workflows . . . . . . . . . . . . . . . . . . 4
1.5 Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.6 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Workflow Management for Business and Science 7
2.1 Workflow Management Systems . . . . . . . . . . . . . . . . . . . 7
2.1.1 Business Processes and Workflow Management . . . . . . . 7
2.1.2 Workflow Modeling . . . . . . . . . . . . . . . . . . . . . 9
2.1.3 Web Services and the Service Oriented Architecture . . . . 13
2.1.4 Alternatives to SOA: The REST architecure style . . . . . . 15
2.1.5 The Business Process Execution Language . . . . . . . . . 16
2.2 Scientific Workflows . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.1 Defining Scientific Workflows . . . . . . . . . . . . . . . . 19
2.2.2 Surveys on Scientific Workflows . . . . . . . . . . . . . . . 20
2.2.3 Motivations for Scientific Workflows . . . . . . . . . . . . 20
2.2.4 Differences to Business Workflows . . . . . . . . . . . . . 21
2.3 Scientific Workflows on the Grid . . . . . . . . . . . . . . . . . . . 22
2.3.1 Grid Computing . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.2 Predecessors of Grid Workflow Systems . . . . . . . . . . . 23
2.3.3 Grid Workflow Management Systems . . . . . . . . . . . . 24
2.4 Life Science Workflows . . . . . . . . . . . . . . . . . . . . . . . . 29
vContents
2.4.1 Bioinformatics Workflow Management Systems . . . . . . 29
2.4.2 BioMoby . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.4.3 Taverna . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
my2.4.4 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.5 The Adoption of BPEL in Scientific Workflow Systems . . . . . . . 38
2.5.1 Scientific Workflows in BPEL . . . . . . . . . . . . . . . . 38
2.5.2 BPEL and the Grid . . . . . . . . . . . . . . . . . . . . . . 39
2.5.3 Collaborative BPEL Development Systems . . . . . . . . . 41
2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3 Workflow Design Processes 47
3.1 Levels of Abstraction and Collaboration in Workflow Design . . . . 47
3.2 Collaborative Workflow Development . . . . . . . . . . . . . . . . 50
3.2.1 An Example of Collaborative Workflow Design . . . . . . . 50
3.2.2 The Collaborative Workflow Design Process . . . . . . . . 52
3.2.3 Requirements of Collaborative BPEL Development Systems 55
3.3 Workflow Development Processes in e-Biology . . . . . . . . . . . 59
3.3.1 Computer Use and Infrastructure in Biology Departments . 59
3.3.2 Roles in e-Biology . . . . . . . . . . . . . . . . . . . . . . 60
3.3.3 The Meta-Process of Workflow Usage in Plant Science . . . 62
3.3.4 e-Biology Use Cases . . . . . . . . . . . . . . . . . . . . . 62
3.3.5 Requirements of e-Biology Workflow Systems . . . . . . . 66
3.4 The development systems HOBBES and CALVIN . . . . . . . . . . 69
4 Collaboration and Consistency 71
4.1 Manifestations of Inconsistency . . . . . . . . . . . . . . . . . . . 71
4.2 Algorithms for Enforcing Consistency . . . . . . . . . . . . . . . . 73
4.3 Consistency in the HOBBES System . . . . . . . . . . . . . . . . . 76
4.4 Late Joining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5 Workflow Metrics 83
5.1 Evening out Intricacies of Collaboration . . . . . . . . . . . . . . . 83
5.2 Workflow Metrics for BPEL . . . . . . . . . . . . . . . . . . . . . 84
5.3 Size Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
5.4 Measuring Control Flow . . . . . . . . . . . . . . . . . . . . . . . 85
5.4.1 McCabe’s Cyclomatic Complexity . . . . . . . . . . . . . . 85
5.4.2 Control-Flow-Complexity . . . . . . . . . . . . . . . . . . 86
5.5 Measuring Parallelism . . . . . . . . . . . . . . . . . . . . . . . . 87
viContents
5.6 Measuring Data Flow Intensity . . . . . . . . . . . . . . . . . . . . 89
5.7 Additional Structure Metrics . . . . . . . . . . . . . . . . . . . . . 90
5.8 Evaluation of the Metrics . . . . . . . . . . . . . . . . . . . . . . . 91
5.8.1 Weyuker’s Properties . . . . . . . . . . . . . . . . . . . . . 91
5.8.2 Weyuker Properties of the DOP Metric . . . . . . . . . . . 92
5.8.3 Weyuker Properties of the DFI Metric . . . . . . . . . . . . 95
5.8.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
5.9 Applying the Metrics: BPEL Code Smells . . . . . . . . . . . . . . 101
5.9.1 Code Smell 1: Similar Functionality, Distinct Complexity . 101
5.9.2 Code Smell 2: Flow Links Sequence . . . . . . . . . . . . . 101
5.9.3 Code Smell 3: Too Many Assigns . . . . . . . . . . . . . . 101
5.9.4 Code Smell 4: Unnecessary Nesting . . . . . . . . . . . . . 102
5.9.5 Code Smell 5: Unexploited Potential Parallelism . . . . . . 103
5.9.6 Code Smell 6: Similar Functionality, Distinct Parallelism . . 103
5.9.7 Code Smell 7: Too Much Computation . . . . . . . . . . . 104
5.10 An Example of Workflow Design and Analysis . . . . . . . . . . . 104
5.10.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.10.2 Original Design . . . . . . . . . . . . . . . . . . . . . . . . 104
5.10.3 Analysis and Redesign . . . . . . . . . . . . . . . . . . . . 106
5.10.4 Further Analysis and Redesign . . . . . . . . . . . . . . . . 107
6 The HOBBES System for Collaborative Workflow Design 109
6.1 BPEL-Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.1.1 Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.1.2 Document Navigation . . . . . . . . . . . . . . . . . . . . 112
6.2 Collaborative Features . . . . . . . . . . . . . . . . . . . . . . . . 113
6.2.1 Workflow Sessions and Phase Management . . . . . . . . . 113
6.2.2 Collaborative Editing . . . . . . . . . . . . . . . . . . . . . 113
6.2.3 Collaborative Activity Configuration . . . . . . . . . . . . . 114
6.2.4 Collaborative Document Navigation . . . . . . . . . . . . . 114
6.2.5 Workflo