Working with DMN Components

Components are what you use to create a Decision Requirements Diagram (DRD). They’re the building blocks for modelling decisions.

In DMN, there are 4 elements, 3 requirements, and 2 artifacts. You find information on specific components and their attributes in the DMN Component Reference.

Component Type Component Description Notation
Element Decision Determines an output value based on Input Data and a defined decision logic.
Input Data The information used as an input by one or more Decisions in order to determine the output value.
Business Knowledge Model A function that encapsulates business knowledge.
Knowledge Source An authority for a Business Knowledge Model or Decision.
Requirement Information Requirement Connects an Input Data or Decision to another Decision node that requires the information.
Knowledge Requirement Connects a Business Knowledge Model to a Decision or to another Business Knowledge Model that invokes the decision logic.
Authority Requirement Connects an Input Data or a Decision to a dependent Knowledge Source or from a Knowledge Source to a Decision, Business Knowledge Model, or another Knowledge Source.
Artifact Text Annotation Provides additional information about an Input Data, Decision, Business Knowledge Model or Knowledge Source.
Association Connects an Input Data, Decision, Business Knowledge Model or Knowledge Source to a Text Annotation.

Component Attributes

Every component has a set of attributes you can edit. You edit them in the Attributes panel.

The Attributes panel has a tab menu. Every component has an Attributes tab. Depending on the component, the Attributes panel can have additional Attribute tabs. For example, a Decision has an Attributes tab and a Variable, Knowledge Requirement, Information Requirement and Authority Requirement tab.

Some tabs in the Attributes panel are shortcuts to global Decision Definitions. Definitions is where you define the parts of a decision that don’t have a graphical representation.

To open the Attributes panel:

  • Select the component in the diagram, and in the Panel menu, click Attributes.

Add Elements

There are several ways to add elements to a diagram. You can add them using the Element Palette, the Ring, Magnetic Edge and by copy and paste.

Add Elements - Element Palette

The Element Palette contains all the elements you can use in a diagram.

To add an element:

  • Select an element from the palette, then drag and drop it onto the diagram.

Add Elements - Ring

The Ring is an interactive context menu that helps you to model decisions faster than manually dragging and dropping elements onto a diagram.

The Ring is divided in two parts: a right menu and a left menu.

The right menu contains actions for adding elements and automatically connects them. The left menu contains tools to edit the element.

Depending on the element you select, the Ring contains the actions and tools you can use for that element.

Hover over icons to see tooltips that help you understand the actions they perform.

Add Elements - Copy and Paste

You can add elements by copying an existing element and pasting it onto another part of the diagram.

  1. Select the element you want to copy and in the left Ring menu, click .

  2. Click an empty space on the diagram, open the Ring and click .

Add Elements - Magnetic Edge

You can activate the magnetic edge tool to automatically connect elements as you drag and drop them onto the diagram.

The tool acts like a magnet and connects to the closest element.

  1. In the Toolbar, click .

  2. Select an element from the Element Palette and drag and drop it onto the diagram.

  3. Select another element and drag it near the element you want to connect it to. Hold the element and drag it into position, then drop it.

    To deactivate the tool, in the Toolbar, click .

Hide Elements

You can hide elements in a diagram when you want to focus on an area of the decision tree without the distraction of unwanted elements.

When you hide an element, the marker is added to the elements the hidden element was connected to.

The elements you hide are placed in the Element Palette under the Available Elements section.

You can restore a hidden element. If the hidden element was connected to other elements, the links are automatically restored.

To hide an element:

  1. Select the element.

  2. In the Ring, click .

To restore a hidden element to a diagram:

  1. In the Element Palette, in Available Elements, select the element, hold, then drag and drop it onto the diagram.

Tools for Editing Elements

Cardanit has several tools that enable you to edit elements in a diagram.

You can use them to create space between elements, align them, select elements, delete them and more.

Edit with the Ring

You can use the left menu of the Ring to edit elements.

Depending on the element you select, the Ring contains the editing tools you can use for that element.

Hover over icons to see tooltips that help you understand the actions they perform.

Tool Icon Description
Copy Copy the element.
Hide Hide the element.
Paste Paste the element.
Delete Delete the element.
Add label Edit a Text Annotation.
Undo Undo actions.
Redo Redo actions.

Create Space Tool

You can use the create space and remove space tools if you need to create space for additional elements or reduce the diagram size.

Create Space
  1. Click .

    The moment you activate the tool, guides appear in the diagram.

  2. Position the pointer over the area of the diagram where you want to create space.

  3. Click, hold and drag in the direction you need to create space — horizontally or vertically — then release.

    To deactivate the tool, click again or press ESC.

Remove Space
  1. Click .

  2. Position the pointer over the area where you want to remove space.

  3. Click, hold and drag in the direction you need to remove space — horizontally or vertically — then release.

    To deactivate the tool, click again or press ESC.

Select Elements

There are several ways to select elements in a diagram.

You can select an element by clicking on it or by using the Rectangular Selection or Select All tools.

Once you’ve selected the elements you can move, copy, delete or align them.

Rectangular Selection Tool

This tool enables you to select multiple elements in the diagram.

  1. In the Toolbar, click .

  2. Click and drag the pointer to define an area around the elements you want to select.

    To deactivate the tool, click again or press ESC.

Select All Tool

This tool enables you to select all the elements in the diagram.

  • In the Toolbar, click .

    To deactivate the tool, click again or press ESC.

Align Elements

You can align and distribute one or multiple elements using the Ring or align and distribute them manually using guides and margins.

Align with Ring

Use the Ring to align elements vertically or horizontally.

When you align elements vertically you can also align them to the right, left and in the center.

When you align elements horizontally you can also align them at the top, bottom or in the middle.

  1. Select the elements you want to align.

  2. Use the alignment options in the right Ring menu.

Align Manually

If you’re adding elements from the Element Palette you can use the guides that appear to help you align the elements.

Vertical and horizontal guides appear when you drag and drop an element near another element. Margins also appear to help you distribute the elements evenly.

Delete Elements

To delete elements in a diagram, select the element or elements:

  • In the Toolbar, click .

  • In the Ring, .

  • Use the keyboard shortcut Ctrl + X.

Undo and Redo

When you’re adding elements to a diagram and editing them it can be useful to undo and redo your actions.

You find the undo and redo actions in the Toolbar and in the Ring.