Process-Driven Applications with BPMN (eBook)

Dr. Volker Stiehl studied computer science at the Friedrich-Alexander-University of Erlangen-Nuremberg. After 12 years as developer and consultant at Siemens, he joined SAP in 2004. As Chief Product Expert, Volker is currently a member of the product management team for SAP Net Weaver Process Integration, SAP's reliable/high performance SOA middleware product for system integrations. Volker is a regular speaker at various national and international conferences and also a lecturer at the University of Erlangen-Nuremberg and the Baden-Wuerttemberg Cooperative State University Mosbach.

1: Introduction 19
1.1 Enterprise Application Software in the Age of Globalization 19
1.2 Book Structure 24
1.3 SOA and Process-Driven Applications 25
1.3.1 Commonalities 26
1.3.2 Differences 27
1.3.3 Process-Driven Application, Process-Driven Architecture 30
2: Definition of Process-Driven Applications 31
2.1 A Brief History: From xApps to Process-Driven Applications 32
2.2 Process-Driven Applications in Comparison with Alternative Application Categories 35
2.2.1 Requirements for Enterprise Application Software in Distributed Environments 36
2.3 Definition and Properties of Process-Driven Applications 37
2.4 The Role of BPMN (Business Process Model and Notation) for Process-Driven Applications: Basics 41
2.4.1 BPMN Core Elements 44
2.4.1.1 Semantics of Process Models 45
2.4.1.2 Events 46
2.4.1.3 Gateways 47
2.4.1.4 Activities 47
2.4.2 Explanation of the Process Using a Simplified Order Process 48
2.5 Example Processes for Process-Driven Applications 51
2.5.1 Master Data Processing 51
2.5.2 Troubleshooting in Project Management 53
2.5.3 Resource Planning for Shift Workers 55
2.5.4 Damage Reports in the Public Sector 57
3: Architecture of Process-Driven Applications 60
3.1 Methodical Approach: Top-Down 61
3.2 Specification of Process-Driven Applications 65
3.2.1 General Information About the Process-Driven Application 66
3.2.2 Process Information 67
3.2.2.1 General Process Information 68
3.2.2.2 Involved Process Roles 69
3.2.2.3 Visualization of the Process Flow 69
3.2.2.4 Detailed Information About the Process Steps 72
3.2.2.5 Description of the Data Flow Within the Process (Process Context) 72
3.2.3 Exception Handling 73
3.2.4 Business Objects 74
3.2.5 User Interfaces 76
3.2.6 Services 77
3.2.7 Importance of the Canonical Data Model 80
3.2.8 Cooperation Between Business and IT Experts 83
3.3 Introduction to the Basic Architecture of Process-Driven Applications 84
3.3.1 Evolution of a Business Model into an Executable Process 84
3.3.2 Advantages and Disadvantages of a Process-Driven Architecture 91
3.3.3 Separation of Business Processes and Technical Processes 93
3.3.4 Loose Coupling 95
3.3.4.1 Physical Connection 95
3.3.4.2 Communication Style 96
3.3.4.3 Data Model/Type System 97
3.3.4.4 Binding 97
3.3.4.5 Platform Specifics 98
3.3.4.6 Interaction Pattern 98
3.3.4.7 Transaction Security 99
3.3.4.8 Control of Business Logic 99
3.3.4.9 Versioning 100
3.3.5 Task Distribution and Interaction Between the Process-Driven Application and the Service Contract Implementation Layer 101
3.3.5.1 Process-Driven Application (Business Composition): Focus on User-Centric Processes 101
3.3.5.2 Service Contract Implementation Layer (Technical Composition): Focus on Integration-Centric Processes 106
3.3.5.3 Interaction Between the Process-Driven Application and the Service Contract Implementation Layer 110
3.3.5.4 Including an ESB in the Service Contract Implementation Layer 117
3.4 Service Repositories and Process-Driven Applications 123
5: Advanced Concepts for Architecture Support in Process-Driven Applications 189
5.1 Locking Behavior of the Connected Systems 189
5.2 Idempotence 192
5.3 Events 193
5.4 Error Handling 196
5.5 Wizard UIs vs. UIs in Process Steps 198
5.6 Patterns 202
5.6.1 Composition Patterns 203
5.6.2 Integration-Centric Patterns 212
5.6.2.1 Aggregator Pattern 213
5.6.2.2 Resequencer Pattern 222
5.6.3 Enhancement Proposal for BPMN for Dedicated Modeling of Integration Processes 226
5.6.3.1 Pattern Symbols as BPMN Language Extensions for Meaningful Representation of Integration Processes 227
5.6.3.2 Aggregator Pattern 229
5.6.3.3 Content Enricher Pattern 232
5.6.3.4 Content Filter Pattern 233
5.6.3.5 Message Translator Pattern 234
5.6.3.6 Content-Based Router Pattern 235
5.6.3.7 Message Filter Pattern 236
5.6.3.8 Recipient List Pattern 236
5.6.3.9 Resequencer Pattern 237
5.6.3.10 Splitter Pattern 240
5.6.3.11 Composed Message Processor Pattern 241
5.6.3.12 Scatter-Gather Pattern 243
5.6.3.13 Extensions for Messages 244
5.6.3.14 Using the Extended BPMN in Specific Scenarios 245
5.6.3.15 Comments on the Extended BPMN 249
5.7 More Flexibility by Combining Rules with Analytical Applications 250
5.7.1 Using Business Rules to Increase Flexibility 252
5.7.2 Using Business Rules in Technical Processes 264
5.7.3 Increasing Automation by Combining Business Rules and Analytical Applications 270
5.8 Process-Driven Applications and Unpredictable Process Flows 272
6: Conclusion and Outlook 291
6.1 Outlook 292
6.1.1 Increasing Flexibility Using Modification-Free Extensions 292
6.1.2 What About Cloud and On-Demand Computing , Software as a Service, Mobile Applications, and Main Memory Databases? 295
6.1.2.1 Software as a Service, On-Demand and Cloud Computing 295
6.1.2.2 Mobile Applications 296
6.1.2.3 Main Memory Databases 297
6.1.3 Does REST Have Implications for Process-Driven Applications? 298
Epilogue 301
Appendix A BPMN Notation 302
Appendix A.1 Core Elements of BPMN 302
Appendix A.2 Events 305
Appendix A.3 Gateways 306
Appendix A.4 Task Types 309
Appendix B Excursus on Service Management: A Comparative Study of Approaches 311
Appendix B.1 Three-Schema Architecture 311
Appendix B.2 Semantic Web Technologies 313
Appendix B.3 Self-Organization and Collective Intelligence 315
Appendix C List of Abbreviations 316
Appendix D GlossaryAll glossary terms marked with (*) are reproduced with the kind permission of Nicolai Josuttis (Josuttis 20... 319
References 334
Index 338