# BPMN data objects and stores

Data objects show information flowing through a process; data stores show information that persists beyond it. Both are artifacts, so they do not affect the flow.

They are optional, and worth adding when a reader would otherwise ask where a document came from.

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## When it matters

* Processes where documents or records are the subject.
* Compliance documentation, where the data trail is the requirement.

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## The symbols

| **Symbol**            | **Means**                                                       |
| --------------------- | --------------------------------------------------------------- |
| Data object           | Page-corner icon. Information used or produced by an activity.  |
| Data input and output | Data object with an arrow, at the process boundary.             |
| Data store            | Cylinder. Information outside the process, persisting after it. |
| Data association      | Dotted arrow linking data to an activity.                       |

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## A few things that catch people out

* Data associations are dotted and directional; they are not sequence flow.
* Data objects do not persist beyond the process instance. Use a data store when they should.
* Do not model every field. Model the documents a reader would ask about.

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## Related

[BPMN groups and annotationsNotes that carry no semantics.](https://help.gocapable.com/diagrams/bpmn-groups-and-annotations.html)

[BPMN eventsCircles: something happens.](https://help.gocapable.com/diagrams/bpmn-events.html)

[BPMN notation referenceBack to the full symbol reference.](https://help.gocapable.com/diagrams/bpmn-notation-reference.html)

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_Sequence flow stays inside the pool._