BPM1: Introduction to Business Process
Management (BPM)
Contents
1 The World of BPM 2
1.1 Definition and Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 The Role of Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Ways to Engage in BPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Business Processes: Core Concepts 2
2.1 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Core Elements of a Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.4 Process Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 The BPM Lifecycle 3
4 Phase 1: Process Identification 3
4.1 Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.2 Steps in Process Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.3 Process Enumeration (Designation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.4 Process Scoping (Architecture) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.5 Reference Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.6 The Evaluation Phase (Selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 Phase 2: Process Discovery 5
5.1 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.2 The Discovery Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.3 Roles Involved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.4 Key Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.5 Elicitation Techniques – I think important . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.6 Conducting the Modeling Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
What should you be know and what should you be able to do?
You should know:
• how a business process is defined, what the core elements are of a business process are and what
the field of BPM is about
• the di!erent phases in the BPM life cycle, give examples of activities and techniques used in each
of these phases
• what process identification is and how designation and evaluation of business processes serves as a
starting point for BPM initiatives
• what process discovery (= as-is process modelling), who is involved, what the challenges are, what
techniques are used, what their strengths and weaknesses are, and which steps should be undertaken
for modelling as-is processes
You should be able to:
• contrast and compare di!erent elicitation techniques for process modelling
1
,1 The World of BPM
1.1 Definition and Goal
Business Process Management (BPM) is a body of principles, methods, and tools to design, analyze,
execute, and monitor business processes.
1.2 The Role of Technology
Technology evolves the flow of work from classical (manual/industrial) to electronic (IT-driven). How-
ever, technology alone is not the solution.
• The First Rule of Technology (Bill Gates): Automation applied to an e!cient operation will
magnify the e!ciency.
• The Second Rule of Technology: Automation applied to an ine!cient operation will magnify
the ine!ciency.
• Key Relationship: Information Technology → Enables Process Change → Yields Business Value.
(Process Change is crucial)
1.3 Ways to Engage in BPM
There are two primary approaches to changing processes:
Continuous Process Improvement (CPI) Business Process Re-Engineering (BPR)
Does not question the current process struc- Puts into question fundamental assump-
ture. tions and principles.
Identifies issues and resolves them incremen- Aims to achieve breakthroughs (e.g., remov-
tally (step-by-step). ing costly non-value-add tasks).
Table 1: CPI vs. BPR
2 Business Processes: Core Concepts
2.1 Definition
A Business Process is a collection of related events, activities, and decisions involving a number of
actors and objects, which collectively lead to an outcome of value to a customer.
• Examples: Order-to-Cash, Procure-to-Pay, Issue-to-Resolution.
”If it does not make at least three people mad, it’s not a process.” (Hammer and
Stanton)
2.2 Outcomes
Every process leads to outcomes:
• Positive outcomes: Deliver value.
• Negative outcomes: Reduce value.
2.3 Core Elements of a Process
Activities: Active elements (e.g., ”Enter sales order”). They are time-consuming, resource-demanding,
and state-changing.
Events: Passive elements (e.g., ”Sales order entered”). They represent conditions/circumstances and
are atomic/instantaneous.
2
,Business Objects (Data): Organizational artifacts that undergo state changes (e.g., physical or digi-
tal orders).
Actors (Resources): Entities performing activities (Humans or Systems/Software).
2.4 Process Perspectives
To model a process, three perspectives are combined:
1. Control Flow: What needs to be done and when? (Predecessor/successor relationships).
2. Data Perspective: What do we need to work on? (Input/output data).
3. Resource Perspective: Who is doing the work? (Humans and systems).
3 The BPM Lifecycle
The lifecycle is a continuous cycle used to manage processes. (The image with the circular form and
process identification at the top)
1. Process Identification: Identifying processes and prioritizing them.
2. Process Discovery: Modeling the ”As-is” process. → BPM 2-6
3. Process Analysis: Finding insights on weaknesses. → BPM 7-8
4. Process Redesign: Creating the ”To-be” process model. → BPM 9
5. Process Implementation: Creating executable process models. → BPM 10
6. Process Monitoring and Controlling: Conformance and performance checks. → BPM 11-13
Figure 1: The BPM Lifecycle
4 Phase 1: Process Identification
4.1 Goal
To understand the organization, identify its business processes, and prioritize management based on
specific criteria.
3
,4.2 Steps in Process Identification
1. Designation Phase: Enumerate main processes and determine scope (Process Architecture).
2. Evaluation Phase: Prioritize processes (Process Selection, Prioritized Process Portfolio).
4.3 Process Enumeration (Designation)
According to Porter, processes are classified into three types:
1. Core Processes: Generate value directly linked to external customers (e.g., Sales, Distribution,
Production). ”Sell stu!, Deliver stu!.”
2. Support Processes: Provide resources to be used by other processes (e.g., HR, IT, Finance/Accounting,
Indirect Procurement).
3. Management Processes: Provide direction, rules, and practices (e.g., Strategic Management,
Risk Management, Supplier Management).
Figure 2: Core, Support, and Management Processes according to Porter. Exercises and examples in
slides
4.4 Process Scoping (Architecture)
Understanding interrelations between processes.
• Specialization General – special product/service
• Horizontal Scoping (Value Chains): Upstream to downstream flow. A chain of processes
delivering value.
– Rules for horizontal boundaries: Change of key business object, change of granularity, change
in frequency/time, or change in intermediate outcome.
– Typical Core Value Chain: Imagine it → Build it → Sell it. (Specializations exist for Make-
to-Stock vs. Make-to-Order vs. Engineer-to-Order).
• Vertical Scoping (Hierarchy): Main processes broken down into sub-processes.
– Level 1: Process Landscape (High level, Value Chain).
– Level 2: Main Processes (Abstract, build up value chains).
– Level 3: Subprocesses (Detailed, multiple activities).
– Level 4: Process Tasks (Atomic, performed by one person/system).
4.5 Reference Models
Templates used to design process architecture (standardized industry models).
• Examples: ITIL (IT), SCOR (Supply Chain), PCF (Process Classification Framework by APQC),
eTOM (Telecom).
• APQC PCF: Four levels (Category → Process Group → Process → Activity).
4
, Figure 3: Hierarchical view of the process architecture
Figure 4: Example: prioritized process portfolio of an insurance company
4.6 The Evaluation Phase (Selection)
Criteria for selecting which processes to manage/improve first:
1. Importance: Which processes have greatest impact on strategic goals.
2. Health (Dysfunction): Deepest trouble/ine”ciency.
3. Feasibility: Susceptibility to successful management/change.
5 Phase 2: Process Discovery
5.1 Definition
The act of gathering information about an existing process and organizing it into an ”As-Is” process
model.
5.2 The Discovery Steps
1. Defining the setting: Assembling the team.
2. Gathering information: Building understanding.
3. Conducting the modeling task: Mapping systematic flow.
4. Assuring quality: Establishing trust in the model → see in later chapters
5.3 Roles Involved
• Domain Expert: Has the knowledge of how the process works (Process Owner/Participant).
• Process Analyst: Responsible for modeling the process.
5
,5.4 Key Challenges
1. Fragmented Process Knowledge: Di!erent people know di!erent parts of the process; rarely
does one person know it all.
2. Instance Level Thinking: Domain experts think in specific examples (”Every trip is di!erent”)
rather than the general process abstraction.
3. Modeling Knowledge: Domain experts rarely understand formal modeling notation (BPMN).
5.5 Elicitation Techniques – I think important
Techniques used to gather information for the model.
Technique Strengths Weaknesses
Document Analy- Structured information; Indepen- Material may be outdated; Wrong
sis dent of stakeholder availability. level of abstraction.
Observation Context-rich insight; Reality check. Intrusive; Stakeholders may be-
have di!erently when watched
(Hawthorne e!ect).
Automated Dis- Extensive set of cases; Objective Requires event logs (data); Data
covery (Process data; Detailed inquiry. quality issues; ”Garbage in, garbage
Mining) out”.
Interviews Detailed inquiry; Can handle excep- Time-consuming (requires many it-
tions. erations/validations); Inconsistent
terminology.
Workshops Direct resolution of conflicting views; Requires synchronous availability of
Creates shared understanding. key stakeholders (expensive/di”cult
to schedule).
5.6 Conducting the Modeling Task
The logical steps to organize gathered material into a model:
1. Identify Process Boundaries (Start event/trigger and End result).
2. Identify Activities and Events.
3. Identify Resources and their handovers (Who does what).
4. Identify the Control Flow (Sequence, logical connectors).
5. Identify Additional Elements.
6
, BPM2: Essential Process Modelling
Contents
1 Process Modelling Languages Overview 2
2 Petri Nets 2
2.1 Formal Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Execution Semantics (The Firing Rule) . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Workflow Nets (WF-nets) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 BPMN: Basic Control-Flow 3
3.1 Core Flow Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2 Routing Patterns (Gateways) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4 Subprocesses 4
4.1 Types of Subprocesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2 Syntactical Rules for Subprocesses . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 Repetition in BPMN 5
5.1 Block-Structured Repetition (Activity Loop) . . . . . . . . . . . . . . . . . . . . 5
5.2 Parallel Repetition (Multi-Instance) . . . . . . . . . . . . . . . . . . . . . . . . . 5
6 Summary 6
What should you be know and what should you be able to do?
You should know:
• what a process modelling notation is and what the basic control-flow routing patterns are
and how they are modelled in BPMN and Petri Nets
• the workings and use of control-flow modelling constructs in BPMN: gateways, repetition
and reuse
You should be able to:
• understand, explain and create BPMN models with basic modelling constructs such as
gateways, loops and repetition
• Make exercises on workflow nets, in line with the home exercise. Therefore you should
be able to understand and apply the notation and formalization of PN, together with the
concept of a marking and the execution semantics (firing rules)
1
,1 Process Modelling Languages Overview
There are various notations for modelling business processes (UML Activity Diagrams, EPCs,
YAWL, BPEL, etc.).
• Transition Systems: Basic representation, but su!ers from the ”state space explosion”
problem.
• EPCs (Event-driven Process Chains): Developed by A.W. Scheer, used in SAP R/3.
Uses distinct connectors for logic (AND, XOR, OR).
• YAWL (Yet Another Workflow Language): Based on Petri nets but adds specific
workflow patterns (cancelation regions, multiple instances).
2 Petri Nets
Petri nets provide the mathematical foundation for process modelling. They are preferred for
their formal semantics, ability to model concurrency, and analysis techniques. Some examples
and exercises in slides
2.1 Formal Definition
A Petri net system is a tuple (P, T, F, m0 ) where:
• P : Finite set of Places (represented by circles).
• T : Finite set of Transitions (represented by rectangles/squares).
• F : Flow relation (set of directed arcs), where F → (P ↑ T ) ↓ (T ↑ P ).
• m0 : The Initial Marking (distribution of tokens).
Figure 1: Basic Petri Net System Structure
2.2 Execution Semantics (The Firing Rule)
1. Enabling: A transition t is enabled if and only if each of its input places contains at
least one token.
2. Firing: When an enabled transition fires:
• It consumes one token from each input place.
• It produces one token in each output place.
2
,2.3 Workflow Nets (WF-nets)
A Workflow Net is a specific subclass of Petri nets designed to model business processes. To be
a valid WF-net, it must satisfy three conditions:
1. Source Place: There is exactly one input place (start) with no incoming arcs.
2. Sink Place: There is exactly one output place (end) with no outgoing arcs.
3. Strong Connectedness: Every node (place or transition) must be on a directed path
from the start to the end.
• Imagine a ”reset” transition connecting End back to Start; the net must be strongly
connected in this closed loop.
3 BPMN: Basic Control-Flow
BPMN (Business Process Model and Notation) is an OMG standard. It is a graph consisting
of four main element types:
1. Flow Objects: Events, Activities (Tasks), Gateways.
2. Connecting Objects: Sequence Flow, Message Flow, Association.
3. Swimlanes: Pools, Lanes.
4. Artifacts: Data objects, Groups, Annotations.
3.1 Core Flow Elements
• Start Event: Circle (thin border). Triggers the process.
• End Event: Circle (thick border). Terminates the process path.
• Task: Rounded rectangle. An atomic unit of work.
• Sequence Flow: Solid arrow. Defines execution order.
3.2 Routing Patterns (Gateways)
Understanding the distinction between Split and Join behavior is vital for the exam.
3
, Figure 2: OR-example: one or more
Table 1: BPMN Gateway Behaviors
Gateway Type Split Behavior (Divergence) Join Behavior (Convergence)
Exclusive (XOR) Exclusive Decision: Only one Simple Merge: Proceeds imme-
branch is chosen based on condi- diately when any one incoming
tions. XOR-join also exists branch arrives. Does NOT syn-
chronize.
”Either A or B”
Parallel (AND) Parallel Split: All outgoing Synchronization: Waits for to-
branches are activated simultane- kens to arrive on all incoming
ously. branches before proceeding.
”A and B”
Inclusive (OR) Inclusive Decision: One or Inclusive Merge: Waits for
more branches are activated all active incoming branches to
based on conditions. complete.
”A and/or B”
Modelling Guideline: Avoid OR-gateways if possible. If used, like in the image (one or
more), ensure they are structured (OR-split matches OR-join).
4 Subprocesses
Process decomposition is used to handle complexity and improve reusability.
4.1 Types of Subprocesses
Embedded Subprocess: Stored within the same file/parent process. Part of the specific
process flow.
Global (Call) Activity: Stored as a separate file. Referenced by the parent process.
• Visual cue: Thicker border around the activity.
• Benefit: Maximizes reusability across multiple processes.
4
Management (BPM)
Contents
1 The World of BPM 2
1.1 Definition and Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 The Role of Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Ways to Engage in BPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Business Processes: Core Concepts 2
2.1 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Core Elements of a Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.4 Process Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 The BPM Lifecycle 3
4 Phase 1: Process Identification 3
4.1 Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.2 Steps in Process Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.3 Process Enumeration (Designation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.4 Process Scoping (Architecture) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.5 Reference Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.6 The Evaluation Phase (Selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 Phase 2: Process Discovery 5
5.1 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.2 The Discovery Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.3 Roles Involved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.4 Key Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.5 Elicitation Techniques – I think important . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.6 Conducting the Modeling Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
What should you be know and what should you be able to do?
You should know:
• how a business process is defined, what the core elements are of a business process are and what
the field of BPM is about
• the di!erent phases in the BPM life cycle, give examples of activities and techniques used in each
of these phases
• what process identification is and how designation and evaluation of business processes serves as a
starting point for BPM initiatives
• what process discovery (= as-is process modelling), who is involved, what the challenges are, what
techniques are used, what their strengths and weaknesses are, and which steps should be undertaken
for modelling as-is processes
You should be able to:
• contrast and compare di!erent elicitation techniques for process modelling
1
,1 The World of BPM
1.1 Definition and Goal
Business Process Management (BPM) is a body of principles, methods, and tools to design, analyze,
execute, and monitor business processes.
1.2 The Role of Technology
Technology evolves the flow of work from classical (manual/industrial) to electronic (IT-driven). How-
ever, technology alone is not the solution.
• The First Rule of Technology (Bill Gates): Automation applied to an e!cient operation will
magnify the e!ciency.
• The Second Rule of Technology: Automation applied to an ine!cient operation will magnify
the ine!ciency.
• Key Relationship: Information Technology → Enables Process Change → Yields Business Value.
(Process Change is crucial)
1.3 Ways to Engage in BPM
There are two primary approaches to changing processes:
Continuous Process Improvement (CPI) Business Process Re-Engineering (BPR)
Does not question the current process struc- Puts into question fundamental assump-
ture. tions and principles.
Identifies issues and resolves them incremen- Aims to achieve breakthroughs (e.g., remov-
tally (step-by-step). ing costly non-value-add tasks).
Table 1: CPI vs. BPR
2 Business Processes: Core Concepts
2.1 Definition
A Business Process is a collection of related events, activities, and decisions involving a number of
actors and objects, which collectively lead to an outcome of value to a customer.
• Examples: Order-to-Cash, Procure-to-Pay, Issue-to-Resolution.
”If it does not make at least three people mad, it’s not a process.” (Hammer and
Stanton)
2.2 Outcomes
Every process leads to outcomes:
• Positive outcomes: Deliver value.
• Negative outcomes: Reduce value.
2.3 Core Elements of a Process
Activities: Active elements (e.g., ”Enter sales order”). They are time-consuming, resource-demanding,
and state-changing.
Events: Passive elements (e.g., ”Sales order entered”). They represent conditions/circumstances and
are atomic/instantaneous.
2
,Business Objects (Data): Organizational artifacts that undergo state changes (e.g., physical or digi-
tal orders).
Actors (Resources): Entities performing activities (Humans or Systems/Software).
2.4 Process Perspectives
To model a process, three perspectives are combined:
1. Control Flow: What needs to be done and when? (Predecessor/successor relationships).
2. Data Perspective: What do we need to work on? (Input/output data).
3. Resource Perspective: Who is doing the work? (Humans and systems).
3 The BPM Lifecycle
The lifecycle is a continuous cycle used to manage processes. (The image with the circular form and
process identification at the top)
1. Process Identification: Identifying processes and prioritizing them.
2. Process Discovery: Modeling the ”As-is” process. → BPM 2-6
3. Process Analysis: Finding insights on weaknesses. → BPM 7-8
4. Process Redesign: Creating the ”To-be” process model. → BPM 9
5. Process Implementation: Creating executable process models. → BPM 10
6. Process Monitoring and Controlling: Conformance and performance checks. → BPM 11-13
Figure 1: The BPM Lifecycle
4 Phase 1: Process Identification
4.1 Goal
To understand the organization, identify its business processes, and prioritize management based on
specific criteria.
3
,4.2 Steps in Process Identification
1. Designation Phase: Enumerate main processes and determine scope (Process Architecture).
2. Evaluation Phase: Prioritize processes (Process Selection, Prioritized Process Portfolio).
4.3 Process Enumeration (Designation)
According to Porter, processes are classified into three types:
1. Core Processes: Generate value directly linked to external customers (e.g., Sales, Distribution,
Production). ”Sell stu!, Deliver stu!.”
2. Support Processes: Provide resources to be used by other processes (e.g., HR, IT, Finance/Accounting,
Indirect Procurement).
3. Management Processes: Provide direction, rules, and practices (e.g., Strategic Management,
Risk Management, Supplier Management).
Figure 2: Core, Support, and Management Processes according to Porter. Exercises and examples in
slides
4.4 Process Scoping (Architecture)
Understanding interrelations between processes.
• Specialization General – special product/service
• Horizontal Scoping (Value Chains): Upstream to downstream flow. A chain of processes
delivering value.
– Rules for horizontal boundaries: Change of key business object, change of granularity, change
in frequency/time, or change in intermediate outcome.
– Typical Core Value Chain: Imagine it → Build it → Sell it. (Specializations exist for Make-
to-Stock vs. Make-to-Order vs. Engineer-to-Order).
• Vertical Scoping (Hierarchy): Main processes broken down into sub-processes.
– Level 1: Process Landscape (High level, Value Chain).
– Level 2: Main Processes (Abstract, build up value chains).
– Level 3: Subprocesses (Detailed, multiple activities).
– Level 4: Process Tasks (Atomic, performed by one person/system).
4.5 Reference Models
Templates used to design process architecture (standardized industry models).
• Examples: ITIL (IT), SCOR (Supply Chain), PCF (Process Classification Framework by APQC),
eTOM (Telecom).
• APQC PCF: Four levels (Category → Process Group → Process → Activity).
4
, Figure 3: Hierarchical view of the process architecture
Figure 4: Example: prioritized process portfolio of an insurance company
4.6 The Evaluation Phase (Selection)
Criteria for selecting which processes to manage/improve first:
1. Importance: Which processes have greatest impact on strategic goals.
2. Health (Dysfunction): Deepest trouble/ine”ciency.
3. Feasibility: Susceptibility to successful management/change.
5 Phase 2: Process Discovery
5.1 Definition
The act of gathering information about an existing process and organizing it into an ”As-Is” process
model.
5.2 The Discovery Steps
1. Defining the setting: Assembling the team.
2. Gathering information: Building understanding.
3. Conducting the modeling task: Mapping systematic flow.
4. Assuring quality: Establishing trust in the model → see in later chapters
5.3 Roles Involved
• Domain Expert: Has the knowledge of how the process works (Process Owner/Participant).
• Process Analyst: Responsible for modeling the process.
5
,5.4 Key Challenges
1. Fragmented Process Knowledge: Di!erent people know di!erent parts of the process; rarely
does one person know it all.
2. Instance Level Thinking: Domain experts think in specific examples (”Every trip is di!erent”)
rather than the general process abstraction.
3. Modeling Knowledge: Domain experts rarely understand formal modeling notation (BPMN).
5.5 Elicitation Techniques – I think important
Techniques used to gather information for the model.
Technique Strengths Weaknesses
Document Analy- Structured information; Indepen- Material may be outdated; Wrong
sis dent of stakeholder availability. level of abstraction.
Observation Context-rich insight; Reality check. Intrusive; Stakeholders may be-
have di!erently when watched
(Hawthorne e!ect).
Automated Dis- Extensive set of cases; Objective Requires event logs (data); Data
covery (Process data; Detailed inquiry. quality issues; ”Garbage in, garbage
Mining) out”.
Interviews Detailed inquiry; Can handle excep- Time-consuming (requires many it-
tions. erations/validations); Inconsistent
terminology.
Workshops Direct resolution of conflicting views; Requires synchronous availability of
Creates shared understanding. key stakeholders (expensive/di”cult
to schedule).
5.6 Conducting the Modeling Task
The logical steps to organize gathered material into a model:
1. Identify Process Boundaries (Start event/trigger and End result).
2. Identify Activities and Events.
3. Identify Resources and their handovers (Who does what).
4. Identify the Control Flow (Sequence, logical connectors).
5. Identify Additional Elements.
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, BPM2: Essential Process Modelling
Contents
1 Process Modelling Languages Overview 2
2 Petri Nets 2
2.1 Formal Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Execution Semantics (The Firing Rule) . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Workflow Nets (WF-nets) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 BPMN: Basic Control-Flow 3
3.1 Core Flow Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2 Routing Patterns (Gateways) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4 Subprocesses 4
4.1 Types of Subprocesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2 Syntactical Rules for Subprocesses . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 Repetition in BPMN 5
5.1 Block-Structured Repetition (Activity Loop) . . . . . . . . . . . . . . . . . . . . 5
5.2 Parallel Repetition (Multi-Instance) . . . . . . . . . . . . . . . . . . . . . . . . . 5
6 Summary 6
What should you be know and what should you be able to do?
You should know:
• what a process modelling notation is and what the basic control-flow routing patterns are
and how they are modelled in BPMN and Petri Nets
• the workings and use of control-flow modelling constructs in BPMN: gateways, repetition
and reuse
You should be able to:
• understand, explain and create BPMN models with basic modelling constructs such as
gateways, loops and repetition
• Make exercises on workflow nets, in line with the home exercise. Therefore you should
be able to understand and apply the notation and formalization of PN, together with the
concept of a marking and the execution semantics (firing rules)
1
,1 Process Modelling Languages Overview
There are various notations for modelling business processes (UML Activity Diagrams, EPCs,
YAWL, BPEL, etc.).
• Transition Systems: Basic representation, but su!ers from the ”state space explosion”
problem.
• EPCs (Event-driven Process Chains): Developed by A.W. Scheer, used in SAP R/3.
Uses distinct connectors for logic (AND, XOR, OR).
• YAWL (Yet Another Workflow Language): Based on Petri nets but adds specific
workflow patterns (cancelation regions, multiple instances).
2 Petri Nets
Petri nets provide the mathematical foundation for process modelling. They are preferred for
their formal semantics, ability to model concurrency, and analysis techniques. Some examples
and exercises in slides
2.1 Formal Definition
A Petri net system is a tuple (P, T, F, m0 ) where:
• P : Finite set of Places (represented by circles).
• T : Finite set of Transitions (represented by rectangles/squares).
• F : Flow relation (set of directed arcs), where F → (P ↑ T ) ↓ (T ↑ P ).
• m0 : The Initial Marking (distribution of tokens).
Figure 1: Basic Petri Net System Structure
2.2 Execution Semantics (The Firing Rule)
1. Enabling: A transition t is enabled if and only if each of its input places contains at
least one token.
2. Firing: When an enabled transition fires:
• It consumes one token from each input place.
• It produces one token in each output place.
2
,2.3 Workflow Nets (WF-nets)
A Workflow Net is a specific subclass of Petri nets designed to model business processes. To be
a valid WF-net, it must satisfy three conditions:
1. Source Place: There is exactly one input place (start) with no incoming arcs.
2. Sink Place: There is exactly one output place (end) with no outgoing arcs.
3. Strong Connectedness: Every node (place or transition) must be on a directed path
from the start to the end.
• Imagine a ”reset” transition connecting End back to Start; the net must be strongly
connected in this closed loop.
3 BPMN: Basic Control-Flow
BPMN (Business Process Model and Notation) is an OMG standard. It is a graph consisting
of four main element types:
1. Flow Objects: Events, Activities (Tasks), Gateways.
2. Connecting Objects: Sequence Flow, Message Flow, Association.
3. Swimlanes: Pools, Lanes.
4. Artifacts: Data objects, Groups, Annotations.
3.1 Core Flow Elements
• Start Event: Circle (thin border). Triggers the process.
• End Event: Circle (thick border). Terminates the process path.
• Task: Rounded rectangle. An atomic unit of work.
• Sequence Flow: Solid arrow. Defines execution order.
3.2 Routing Patterns (Gateways)
Understanding the distinction between Split and Join behavior is vital for the exam.
3
, Figure 2: OR-example: one or more
Table 1: BPMN Gateway Behaviors
Gateway Type Split Behavior (Divergence) Join Behavior (Convergence)
Exclusive (XOR) Exclusive Decision: Only one Simple Merge: Proceeds imme-
branch is chosen based on condi- diately when any one incoming
tions. XOR-join also exists branch arrives. Does NOT syn-
chronize.
”Either A or B”
Parallel (AND) Parallel Split: All outgoing Synchronization: Waits for to-
branches are activated simultane- kens to arrive on all incoming
ously. branches before proceeding.
”A and B”
Inclusive (OR) Inclusive Decision: One or Inclusive Merge: Waits for
more branches are activated all active incoming branches to
based on conditions. complete.
”A and/or B”
Modelling Guideline: Avoid OR-gateways if possible. If used, like in the image (one or
more), ensure they are structured (OR-split matches OR-join).
4 Subprocesses
Process decomposition is used to handle complexity and improve reusability.
4.1 Types of Subprocesses
Embedded Subprocess: Stored within the same file/parent process. Part of the specific
process flow.
Global (Call) Activity: Stored as a separate file. Referenced by the parent process.
• Visual cue: Thicker border around the activity.
• Benefit: Maximizes reusability across multiple processes.
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