Events

• Timer
  • Attributes
• Condition
  • Start Event ‘Condition’ for Event Subprocess (Conditional Start Event)
  • Boundary Event ‘Condition’ (Conditional Boundary Event)
  • Intermediate Catching Event ‘Condition’ (Conditional Intermediate Catch Event)
  • Attributes
  • Top-Down Evaluation
  • Scope-Based Evaluation
  • Examples
• Error
  • Start Event ‘Error’
  • End Event ‘Error’
  • Intermediate Event ‘Error’
• Signals
  • Event (Signal) Definitions
  • Event Payloads
  • Examples of Event Configurations
• Termination
• Event Subprocess

An Event is one of the key BPMN elements. Unlike a task, which describes an action (what needs to be done), an event describes a fact that occurs during the process and affects its execution: it starts the process, changes its course, or ends it. Examples of events: deadline expiration, receiving a signal from an external system, occurrence of an error.

Graphical event elements in BPMN are classified based on the event’s position in the process diagram:

	Initial (start) event (initiating the business process)/ Start event
	Intermediate Event
	Final event (ending the business process) / End event

Intermediate events - events that are located between the start and end events in BPMN. Such events are depicted using a double line. Intermediate events are divided into:

• Catching – waiting events. During a catching event, process execution is suspended. Such events are not attached to any task:

  

  Place an intermediate event on the diagram, click the wrench in the context menu, and select one of the possible subtypes:

  

• Boundary interrupting – events that are attached to an activity (e.g., a task) and are located on the border (boundary) of the activity element in the diagram.

  

  Boundary events are divided into two classes:

  • boundary interrupting (marked as 1 in the figure)

  • boundary non-interrupting (marked as 2 in the figure)

  If there is an interrupting event for a task, it is necessary to wait until it occurs (e.g., until the application is confirmed). This task cannot be performed in parallel.

  Waiting for a non-interrupting event does not suspend task execution. For example, at any moment, the consideration of an application can be moved to a higher level, but until such a message is received, the task execution (considering the application) should be performed at a lower level.

  Drag the intermediate event element onto the border of a task or another element, and then select the required type by clicking the wrench image in the context menu.

  

• Throwing

  When the flow of control reaches a throwing event, the corresponding processing occurs immediately (a message is sent, a signal is triggered, etc.), after which the flow of control immediately leaves the current element and continues further along the process.

  

  The border is the same as for a catching event, but according to the BPMN standard, the image inside a throwing event is filled with black.

  Place an intermediate event on the diagram, click the wrench in the context menu, and select one of the possible subtypes:

  

Currently, the following event types are available in Citeck:

	Timer	Used for modeling recurring events. The timer can also be used to model points in time, time intervals, and exceeding time limits.
	Conditional	Used to model the business process’s reaction to changing conditions.
	Error	Used to model possible errors during process execution, as well as to display the sequence of actions to resolve these errors.
	Signal	Denotes waiting for or sending a signal between processes; integration with Citeck events is used.
	Termination	Causes immediate termination of process execution, and all its active control flows are interrupted.