Business Process Modeling with BPMN

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1 member of Business Process Modeling with BPMN Knut Hinkelmann

2 Elements of BPMN Elements of BPMN can be divided into 4 categories: Flow Objects Connectors Artefacts Swimlanes Activities Sequence Flow Data Objects Pool Text Annotation Events Message Flow text Group Lanes (within a Pool) Gateways Associations

3 Activities An Activity is work that is performed within a Business Process. An activity has a well-defined start and end. A Task is an atomic activity, which is not broken down further. When marked with a [+] symbol, it indicates a Subprocess.

4 Activities A Task is a unit of work, the job to be performed. When marked with a [+] symbol it indicates a Sub- Process, an activity that can be refined. A Transaction is a set of activities that logically belong together; it might follow a specified transaction protocol.. An Event Sub-Process is placed into a Process or Sub-Process. It is activated when its start event gets triggered and can interrupt the higher level process context or run in parallel (non-interrupting) depending on the start event. A Call Activity is a wrapper for a globally defined Sub-Process or Task that is reused in the current process. Business Architecture - Business Process Modeling 4

5 Types of Tasks A User Task is executed by a person, with the assistance of an application. A Manual Task requires human involvement to complete. In contrast to a User Task, a Manual Task is expected to be performed without an application A Service Task does not require any human interaction. It is completed automatically by using some sort of an external service (web service or application).

6 Task Types Types specify the nature of the action to be performed. They can be identified by a symbol inside the object. Business Process Modeling, BPMN 6

7 Subprocesses A Subprocess is a compound activity, i.e. an activity with subparts that can be described as a child-level process in another process diagram. Reasons for using subprocesses Top-down modelling Reuse and consistency Details of subprocess «Process order»

8 Activity Markers Markers indicate execution behavior of activities / subprocesses Business Process Modeling, BPMN 8

9 Style Rules: Naming of Activities Activities should be given names of the form VERB-NOUN. Check credit (action), not Credit check (function) Approve loan (action), not Loan approval (function) or Loan approved (state)

10 Order of activities The sequence flow is used to describe the order of activities

11 Start and End Events A process must be triggered by a start event Each flow must end in an end event

12 Delay in the Process Flow Do you see the problem?? Intermediate events are used, if some activity should be delayed In the example, there is a delay after «send offer» the process continues with «Process order», as soon as the confirmation is received

13 Events Events are states that affect the flow of the process. Start Event Intermediate Event End Event Events are represented as circles. The type of boundary determines the type of Event Start Event: single line Intermediate Event: double line End Event: thick line

14 Types of Start and End Events Message Timer Conditional Start Events and Intermediate Events are triggers (catching) Start event triggers a proces Intermediate event triggers an activity Types of trigger events: Message Event: Arrival of a message (application arrived) or object (product delivered) Timer: point in time (e.g. 19:00) or duration (e.g. 2 hours) Conditional: Condition or business rule (e.g. temperature above 200 )

15 Events during Activity Execution Events on the boundary of an activity: catch an event that occurs during the execution of the activity Events in sequence flow: catch an event after the execution of the previous activity Boundary events can be interrupting non-interrupting

16 Catching and Throwing Intermediate Events A catching intermediate event, with the wide icon inside, means the process waits for the trigger signal When the trigger signal arrives, the process resumes on the sequence flow A throwing intermediate event, with the black icon inside, means the process generates the trigger signal Note: Start events are catching End events are throwing Business Process Modeling, BPMN 16

17 Catching and Throwing Process 1 Process 2 Process 3 Throwing events can be used to synchronize processes Example: When the task «check account» in process 1 is finished, the money is received (throwing event «money received») As soon as the event «money received» occurs, process 2 can be continued and process 3 can start.

18 Event-Types Business Process Modeling, BPMN 18

19 Event types you need to know Adapted from: Silver, B. (2011). BPMN Method and Style, Second Edition. Aptos, CA: Cody-Cassidy Press. Figure 7-2 Business Architecture 19

20 Style: Naming of Events Events should be given names that represent a state Noun-State, e.g. Loan approved, Message received Duration (e.g. 2 hours) or point in time (e.g. 16:00, Monday) Condition, e.g. Temperature > 200

21 Exclusive Gateway Only one of several alternatives should be executed: Exclusive Gateway: marked with «X» (or without marker). Gateway is labelled with a question Outgoing sequence flows are labelled with possible answers

22 Data-based vs. Event-based Exclusive Gateways Compare:

23 Parallel Gateway Several paths must be followed: Parallel Gateway: marked with «+». All paths are executed Order of execution does not matter Executions can overlap Parallel paths must be synchronized with parallel gateway.

24 Inclusive Gateway Several paths can be followed: Inclusive Gateway: marked with «O». Any combination of paths can be executed Inclusive paths must be synchronized with inclusive gateway

25 Information Flow Information flow within a process is represented with data objects and data stores Dats stores can be used to represent information flow between processes

26 Assigning Tasks to Performers A Pool is a container for a business process or a participant in a collaboration A Lanes represent performers of a process A Lane can represent a role, an organisational unit or a system. Activities within a lane are executed by the performer that is represesented by the lane

27 Assigning Tasks to Performer (2) An activity is the only BPMN element that has a performer. Only the assignment of activities to lanes are important. Gateways, events, data objects can be placed anywhere =

28 External participants

29 Rules for Pools and Lanes External participants are modeled as (collapsed) pool Exchange between pools is represented by message flow Message Flow MUST NOT connect elements within a pool Information flow within a pool is represented by data objects data store Sequence flow MUST NOT cross pool boundaries

30 Some Guidelines for Good Modeling

31 Style: Primary Modeling Direction There is a primary modeling direction left to right (horizontal lanes) top to bottom (vertical lanes) Use back arrows only for loops

32 Style Rules for Pools and Lanes Use a black-box (=collapsed) pool to represent the Customer or other external requester or service provider Begin customer-facing processes with a Message start event receiving a message flow from the Customer pool. Label process pools with the name of a process; label blackbox pools with a participant role or business entity.

33 Style Rules for Pools and Lanes If you can, model internal organizational units as lanes within a single process pool, not as separate pools. Separate pools imply independent processes.