Preface	6
	Contents	8
	1 Introduction	12
	1.1 Motivation	13
	1.2 Intended Readership and Relevance	18
	1.3 Outline	19
	2 State of the Art	20
	2.1 An Overview of Business Process Modelling Techniques	20
	2.2 Formal Representations of BPMN	22
	2.3 Suitability of BPMN for Business Process Modelling	24
	3 Modelling Semantics with Abstract State Machines	28
	3.1 General Features of the ASM Method	29
	3.2 The ASM Notation Used in This Book	33
	3.2.1 Rules	33
	3.2.2 Derived Functions	35
	3.2.3 Local Constants and Variables and New DataElements	35
	3.2.4 Assertions	36
	3.2.5 Types of Functions and Universes	36
	3.2.6 Signatures of Functions and Rules	37
	3.2.7 Boolean Expressions	37
	3.2.8 Set Expressions	38
	3.2.9 Naming Conventions	38
	4 A Rigorous Semantics for BPMN 2.0 Process Diagrams	40
	4.1 Process Diagrams	41
	4.2 Framework	44
	4.2.1 Initialisation and Top-Level Process Management	44
	4.2.2 Workflow Transition Interpreter	45
	4.2.2.1 Token Concept	46
	4.2.3 Flow Nodes	47
	4.2.3.1 Node Transition	49
	4.2.3.2 Instance Transition	51
	4.2.3.3 Process vs. Activity	51
	4.3 Control Flow	53
	4.3.1 Producing Tokens	54
	4.3.2 Consuming Tokens	54
	4.4 Instantiation, Deletion, and Interruption	55
	4.4.1 Creating Instances	55
	4.4.2 Deleting Instances	56
	4.4.3 Interrupting Activities	57
	4.5 Activities	60
	4.5.1 Send Tasks and Receive Tasks	62
	4.5.2 Common Semantics of Activities	63
	4.5.3 Tasks	67
	4.5.4 Sub-processes	71
	4.5.5 Event Sub-processes	74
	4.5.6 Transaction Sub-processes	75
	4.5.7 Ad Hoc Sub-processes	78
	4.5.8 Compensation	80
	4.5.8.1 Rules Concerning Compensation	81
	4.5.8.2 Functions Concerning Compensation	82
	4.5.9 Call Activities	82
	4.5.10 Loop Activities	84
	4.5.10.1 Standard Loop	88
	4.5.10.2 Sequential Multi-instance Loop	90
	4.5.10.3 Parallel Multi-instance Loop	92
	4.6 Gateways	94
	4.6.1 Parallel Gateways	97
	4.6.2 Exclusive Gateways	99
	4.6.3 Inclusive Gateways	101
	4.6.4 Complex Gateways	107
	4.6.5 Event-Based Gateways	113
	4.7 Events	117
	4.7.1 Event Transition	119
	4.7.2 Catching Events	119
	4.7.3 Start Events	124
	4.7.4 Start Events of Top-Level Processes	126
	4.7.5 Start Events of Embedded Sub-processes	133
	4.7.6 Start Events of Event Sub-processes	134
	4.7.7 Boundary Start Events	139
	4.7.8 Intermediate Catching Events	142
	4.7.9 Catching Link Events	145
	4.7.10 Intermediate Boundary Events	147
	4.7.11 Throwing Events	151
	4.7.12 End Events	154
	4.7.13 Intermediate Throwing Events	155
	4.7.14 Throw a Compensation Event	156
	4.7.14.1 Throw an Exception	158
	4.8 Data	159
	4.9 Miscellaneous	161
	4.9.1 Scope	161
	4.9.2 Message Flow	161
	4.9.3 Swimlanes	162
	4.9.4 Artefacts	163
	4.9.5 Conversation	163
	4.9.6 Correlation	163
	4.9.7 Choreography	163
	5 How the Semantic Model Can Be Used	164
	5.1 Validation and Verification	165
	5.2 Validation	166
	5.3 Verification	169
	6 A Discussion of BPMN 2.0	171
	6.1 General Remarks on BPMN	172
	6.2 Deviations Between Our Model and the BPMN 2.0 Standard	175
	6.2.1 Conflicting Provisions in the Standard	175
	6.2.2 Superfluous Elements	176
	6.3 Suggestions for Further Improvements	177
	6.3.1 Potential for Semantic Simplification	177
	6.3.2 Process Instantiation by Mixed-Behaviour Elements	178
	6.3.3 Other Mixed-Behaviour Elements and Further Possible Simplifications	181
	6.3.4 Object-Oriented vs. Subject-Oriented Approaches	182
	6.3.5 Modelling Issues Currently not Covered by BPMN	183
	7 Towards a Workflow Engine by Stepwise Refinement	184
	7.1 Workflow Interpreter (WI)	184
	7.2 Context	186
	7.2.1 Static Context	186
	7.2.2 Root Context	187
	7.2.3 Sub-context	187
	7.3 Notifications	188
	7.4 Implicit Notifications	190
	7.5 Message and Signal Pool	191
	7.6 Event Publication	192
	7.7 Event Propagation	193
	7.8 Deployment Manager and Deployments	194
	7.8.1 Deployments	194
	7.8.2 Deployment Manager	195
	7.9 Instance Manager	196
	7.10 Further Refinements	198
	8 Discussion of the Proposed Specification and Outlook	199
	8.1 Deontic BPMN	200
	8.2 A Layered Approach for Actor Modelling	201
	8.3 Integration of User Interaction Modelling	202
	8.4 Towards an Enhanced Communication Concept	203
	8.5 Integration of Data Modelling	204
	8.6 Towards an eP2 Architecture	205
	A The Signature of the Ground Model	206
	A.1 Auxiliary Functions and Constructs Used	206
	A.2 Basic Functions (Signature)	208
	A.2.1 Primitive Types	208
	A.2.2 Universes	209
	A.2.2.1 Regarding Flow Nodes and Connecting Objects	210
	A.2.2.2 Regarding Lifecycle States	211
	A.2.2.3 Regarding Event Triggers	212
	A.2.3 Static Functions	214
	A.2.3.1 Regarding Processes	214
	A.2.3.2 Regarding Flow Nodes	215
	A.2.3.3 Regarding Event Definitions	219
	A.2.3.4 Regarding Connecting Objects	219
	A.2.3.5 Regarding Data	220
	A.2.4 Shared Functions	220
	A.2.5 Monitored Functions	221
	A.2.6 Controlled Functions	222
	A.2.6.1 Regarding Instances	222
	A.2.6.2 Regarding Flow Nodes	223
	A.2.6.3 Regarding Connecting Objects	223
	A.2.6.4 Regarding Tokens	224
	A.2.6.5 Regarding Event Triggers	224
	B List of Acronyms	225
	C BPMN Symbols	227
	References	229
	Index	238