BPMN Level 1 Palette

part 1 - getting started

BPMN Basics: Flow Nodes

  • Activity

    • Task (atomic) or

    • Subprocess (compound)

  • Event

    • Start

    • End

    • Intermediate

    • Boundary

  • Gateway

bpmn level 1 basics

BPMN Basics: Connectors

  • Sequence flow

  • Message flow

  • Association

bpmn level 1 connectors

Sequence Flow

  • Describes control flow between flow elements in a process

  • Has exactly one source and one target flow element

  • Can be conditional or non-conditional

  • Can enter event or activity from any angle

  • Cannot pass a (sub) process boundary

  • Not used between pools![1]

bpmn level 1 connectors sequence flows

Start Event

  • Starts a process or subprocess

  • None start event - internal trigger

  • Message start event

    • Start event matched with specific message (name)

    • Useful if there are multiple ways to start a process

  • Timer start event

    • Process started based on time condition (moment or cycle)

bpmn level 1 start events

End Event

  • Ends a path within a process or subprocess

  • None end event - no emission

  • Message end event

    • End event that emits message

  • Terminate end event

    • Ends the (sub)process and terminates any parallel paths

bpmn level 1 end events

Simplest Process Ever

bpmn level 1 simplest process ever

Abstract Task

  • Activity that is atomic (not a subprocess), but unspecified (abstract[2]) w.r.t. its implementation

    • Can be automated

    • Can be manual

  • Often used for high level process models during initial design

  • Not meant for executable models

bpmn level 1 abstract task

Most Generic Process Model Ever

bpmn level 1 most generic process ever

User Task

  • Atomic activity for execution by a human participant

  • Execution of the process path stops as the user task is created

  • Execution path continues after the user indicates the task has been completed

  • Creation, notification and "sending" information to the task is implicit in activity

  • Not necessarily an atomic action

    • User may be required to perform multiple actions

bpmn level 1 user task

Service Task

  • Activity that uses a service when performed

  • Most typically used for modelling automated execution by a service external to the process engine

    • There is no manual action needed before it can start

    • The service can be invoked immediately and the task may wait for the reply

    • A request to invoke the service can be issued[3]

  • Execution continues after the service has been used

bpmn level 1 service task

Parallel Gateway

  • Handles unconditional parallel flows

  • Splitting behaviour

    • Gateway splits incoming flow into all outgoing flows

  • Merging behaviour

    • Gateway merges incoming flows into outgoing flow

      • Proceeds only after all flows have reached gateway

      • All incoming paths must therefore be enabled!

    • Paths must not not be merged

      • But all must reach end event to end process

bpmn level 1 parallel gateway

Exclusive Gateway

  • Handles mutually exclusive flows

  • Splitting behaviour

    • Gateway chooses exactly one outgoing flow for incoming flow

  • Merging behaviour

    • Gateway merges incoming flow into outgoing flow

    • Paths must not be merged

      • But all must reach end event to end process

    • Can be merged into activity implicitly

bpmn level 1 exclusive gateway

Implicit Merge

bpmn level 1 implicit merge

Merging Conditional Paths

bpmn level 1 merging conditional paths incorrect

bpmn level 1 merging conditional paths correct

Process

  • Group of all activities, events and gateways including the flows between them

  • Defines a scope

  • Often invisible at global scope (i.e., the canvas)

bpmn level 1 process

Subprocess

  • Defines scope within another process - can have boundary events[4]

  • Defined in the same file - lifecycle is bound to that of containing process

  • Segments the process into chunks or phases

  • Is a compound activity and follows the semantics for an activity

  • Can be displayed collapsed or expanded (tooling support varies)

  • Starts with a start event and ends with (at least one) end event

bpmn level 1 subprocess

Using Subprocesses

bpmn level 1 using subprocess

Process Example

bpmn level 1 part 1 example

Questions

background
1. Pools will be explained at a later moment.
2. This type of task was referred to as a "None Task" in BPMN 1.2
3. Some process engines provide the option to configure a service task’s work to be retrieved by the service ("pull") instead of being invoked by the process engine ("push")
4. Boundary Events are explained as part of BPMN Level 2