BPMN Link Event

BPMN Link Event

The BPMN Link Event article provides a detailed explanation of the link event BPMN element, including the definition, notation, rules, guidelines and examples.

The BPMN Link Event article delves deep into the intricacies and applications of the link event element as outlined in the BPMN 2.0 specification. The definition, notation, and rules sections offer a concise summary of the BPMN 2.0 Specification pertaining to the link event element. Meanwhile, the guidelines section presents a curated collection of best practices specific to the link event, showcasing its proper and effective utilisation in process modelling.

BPMN Definition

The Link Intermediate Events are only valid in normal flow. A Link is a mechanism for connecting two sections of a Process. Link Events can be used to create looping situations or to avoid long Sequence Flow lines. They can also be used as generic “Go To” objects within the Process level. ~ BPMN Specification

BPMN Notation

The BPMN specification defines the different types of Link Event elements using the following description and notation:

ElementDescriptionNotation
Link Intermediate Catch EventThe token traversing a Sequence Flow would arrive at the Link Intermediate Catch Event (Target) after it “jumped” from the Link Intermediate Throw Event (Source) if the Link Name is the same.
Link Intermediate Throw EventThe token traversing a Sequence Flow would reach the Link Intermediate Throw Event (Source) and then “jump” to the Link Intermediate Catch Event (Target) if the Link Name is the same.

BPMN Event Types: Link Events

BPMN Event Types

BPMN events represent various types of occurrences that affect the flow of a process, and they can be categorized based on their position and behavior in the process.

  • Start Event: The Start Event indicates where a particular Process will start.
  • Intermediate Event: The Intermediate Event indicates where something happens (an Event) somewhere between the start and end of a Process.
  • End Event: The End Event indicates where a Process will end.
  • Catching Events: Events that catch a trigger. All Start Events and some Intermediate Events are catching Events.
  • Throwing Events: Events that throw a Result. All End Events and some Intermediate Events are throwing Events that MAY eventually be caught by another Event.
  • Boundary Event: An Intermediate Event that is attached to the boundary of an Activity.

The following table illustrates how the different types of Link Events are grouped as per the BPMN Event types:

Catching EventsThrowing Events
Start EventIntermediate EventEnd Event
StandardEvent Sub-Process
Interrupting
Event Sub-Process
Non-Interrupting
CatchingBoundary
Interrupting
Boundary Non-
Interrupting
ThrowingStandard
Link Event

BPMN Notation: Link Event

BPMN Diagram

The following is an example of a BPMN Link Event within a diagram:

BPMN Link Event Example of BPMN link Event

The token traversing a Sequence Flow would reach the Link Intermediate Throw Event (Source) and then “jump” to the Link Intermediate Catch Event (Target) and continue down the Sequence Flow. The Process would continue as if the Sequence Flow had directly connected the two objects.

BPMN Standards & Guidelines

The difference between standard and guideline is that a standard is a level of quality or attainment while a guideline is a non-specific rule or principle that provides direction to action or behaviour. A standard are high in authority and needs to be adhered to versus a guideline is low in authority and guide one in setting standards or determining a course of action.

BPMN Standards

The BPMN Standards section contains a list of rules that are applicable to the BPMN Link Event as per the official rules of the BPMN Specification.

  • The Link Intermediate Events are only valid in normal flow and MAY NOT be used on the boundary of an Activity.
  • The Link Event are limited to a single Process level and CAN NOT link a parent Process with a Sub-Process.
  • The Link Event CAN be multiple source Link Events, but there CAN only be one target Link Event.

BPMN Guidelines

The BPMN guidelines section contains a list of optional rules that can be used as a guide.

  • A Link Intermediate Throw Event should have a Text Annotation with the Source: {Link Name} associated with it.
  • A Link Intermediate Catch Event should have a Text Annotation with the Target: {Link Name} associated with it.

Finally

This article provided a detailed explanation of the BPMN Link Event element. Follow me on any of the different social media platforms, and feel free to leave comments.

Reference