# DMN editor

DMN exists because decision logic written as paragraphs becomes ambiguous the moment there is more than one condition. A decision table cannot be ambiguous: every combination either has a result or is visibly missing one.

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## What it is for

| **Instead of**                           | **Model**                                        |
| ---------------------------------------- | ------------------------------------------------ |
| A paragraph describing eligibility rules | A decision table with one row per rule           |
| Nested gateways in a BPMN process        | A single decision task backed by DMN             |
| A spreadsheet nobody can find            | A decision that lives with the process it serves |

## What the editor gives you

![The DMN editor showing a decision requirements diagram in which Decision 2 and Decision 3 feed Decision 1, with a shape palette on the left and a properties panel listing General, Documentation, Varia](https://help.gocapable.com/images/cb6b4d20-3fa9-44ac-bb8e-7e431107963e.webp)

Two supporting decisions feed a third, and the panel on the right holds the properties of whichever element is selected.

* **Decision tables.** Rows, hit policies and the completeness check.
* **Decision requirement diagrams.** How decisions depend on each other and on input data.
* **Standard XML.** DMN that other tools can read.

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## A few things that catch people out

* The hit policy matters. Unique, First and Collect give genuinely different answers to the same table.
* A table with gaps is not an error, but it is usually a bug in the rules. The editor shows you the gaps.
* DMN pairs with BPMN rather than replacing it: the process says when to decide, the decision says how. See [BPMN editor](https://help.gocapable.com/diagrams/editors.html).

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## Related

[BPMN editorThe process around the decision.](https://help.gocapable.com/diagrams/editors.html)

[Diagram typesWhen you need DMN at all.](https://help.gocapable.com/diagrams/diagram-types.html)

[ReferenceDMN version and hit policies.](https://help.gocapable.com/diagrams/reference.html)

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_Rules you can check, not prose you have to interpret._