Participant - Person

A Person represents a human participant or group of people. A Person shares the same symbol as a BPMN Participant with a person icon positioned in the top left comer of the rectangle

An engineer, a customer, a doctor, etc

UML Use case - Actors, BPMN - Human task

Participant - Organization

An Organization represents an abstract or institutional participant in a conversation

A public agency, a company, a bank, etc

UML Use case - Actors, EPC - Organizational unit

Participant - Device

A Device represents a non-human participant in a conversation, capable of autonomously communicating with a human

An artificial conversational entity (i.e., chatbot), a smart sensor, an online service, etc

UML Use case, BPMN-Service task

Participant rule

A Participant rule element specifies conditions that must be assured in order to participate in a specific conversation

Knowledge of specific language, communication technologies, or standards

BPMN- Conditional event, Rule task

Background conversation

The element represents a Participant in a conversation who is simultaneously involved in another conversation; however not modeled in the current diagram but on a referenced one

An analyst is communicating with an engineer, wherein is also involved in another communication with a customer

EPC - Process path

Conversation rule

This type of conversation can only be performed in a case where all involving participants apply the specified rule

Knowledge of a specific language, information-communication technology or relevant standards

BPMN- Conditional event, Rule task

Sequence conversation

This type of conversation is composed of messages sharing the same correlation key and with the standardized order being explicitly specified (i.e., as in the case of ‘underlying’ fully specified collaboration diagrams)

The order of messages when asking for credit is the same in each case

UML Sequence Diagram, BPMN 2.0 - Sequence activity, Sequence flow