# BPMN Conversation Diagram

**In short:** A BPMN conversation diagram gives a very high-level view of which participants exchange messages. It draws each group of exchanges as a hexagon called a conversation.

## Explanation

A BPMN conversation diagram gives a "30,000-foot view" of how participants interact. BPMN is a standard notation for drawing business processes (see BPMN 2.0 Notation). A participant is a party in the exchange, drawn as a pool. Pools are explained in BPMN Swimlane (Pool and Lane).

The diagram shows the messages that pass between those participants. It presents them as conversation objects instead of individual messages.

**Notation rules**

- A conversation is a hexagon drawn with a single thin line.
- A sub-conversation is also a hexagon with a single thin line. It adds a small square marker with a plus sign inside.
- Conversation links are drawn with double thin lines.

The plus marker tells the reader that a hexagon is a sub-conversation, not a plain conversation.

For the notation that shows full message flows, see BPMN Collaboration Diagram. For an overview of all BPMN diagram types, see BPMN Diagram Types.

## Example

Imagine an online shop, a payment provider, and a delivery company. One hexagon, labeled "Order payment," links the shop and the payment provider. A second hexagon, labeled "Shipping," links the shop and the delivery company. A reader sees who exchanges messages with whom, without reading any message detail.

## Trade-offs

The diagram stays at a coarse level. It shows conversations between participants, not the detail of each message. The verified facts say nothing further about when to prefer it over other BPMN diagrams.



## Checks

- Conversations are drawn as hexagons with a single thin line.
- Sub-conversations carry a small square marker with a plus sign.
- Conversation links use double thin lines.

## Related

- [BPMN Collaboration Diagram](https://arc.fuet.ch/concepts/modeling-bpmn/bpmn-collaboration-diagram.md)
- [BPMN Diagram Types](https://arc.fuet.ch/concepts/modeling-bpmn/bpmn-diagram-types.md)
- [BPMN Swimlane (Pool and Lane)](https://arc.fuet.ch/concepts/modeling-bpmn/bpmn-swimlane-pool-and-lane.md)
- [BPMN 2.0 Notation](https://arc.fuet.ch/concepts/modeling-bpmn/bpmn-2-0-notation-overview.md)
- [BPMN Focus on Connected Businesses](https://arc.fuet.ch/concepts/modeling-bpmn/bpmn-focus-on-connected-businesses.md)

## Sources

- [Learning BPMN 2 - Which models are available in BPMN? | ARIS BPM Community](https://ariscommunity.com/users/roland-woldt/2011-01-28-learning-bpmn-2-which-models-are-available-bpmn) — ariscommunity.com, accessed 2026-11-09
- [Conversations :: BPMN Rule Book](https://cloud.trisotech.com/bpmnrulebook/bpmn-rule-book/conversations.html) — cloud.trisotech.com, accessed 2026-11-08
- [How to Draw BPMN Conversation Diagram?](https://www.visual-paradigm.com/tutorials/bpmn-conversation-diagram.jsp) — visual-paradigm.com, accessed 2026-11-09