How to Create a Decision Table: A Step-by-Step Guide

Step 1: Starting a New Decision Table Diagram

Open Software Ideas Modeler and navigate to the Project tab in the top ribbon.
In the Content group, click on Add New Diagram button.
A dialog box will appear. On the left side, scroll through the categories and select Other.
From the list of diagram types on the right, choose Decision Table.
In the Name field at the bottom, type Customer Benefits (our example) or any other relevant name for your table.
Click OK to create the diagram.

Conditions represent the factors that influence your decisions. Let’s add a few key conditions to our table.

In the toolbar at the top of the screen, click Add Condition.
A Condition dialog box will appear. In the Name field, type 'Is the customer a premium member?'.
The default Yes/No condition type is suitable for this example, so no need to change it. - Click OK.
The condition will now appear in the table.

Repeat the process by clicking Add Condition again.
In the Name field, type Total purchase amount.
Change the type from Yes/No to Number by clicking on the radio button, allowing numerical input for this condition.
Click OK.
Finally, click Add Condition once more.
In the Name field, type Preferred free sample.
Change the type to Custom Choice. A text area bellow the option will be enabled where you can enter options.
Type the following options, one per line: Apple, Banana, and Cherry.
Click OK.

Now you have three conditions in your table: whether the customer is a premium member, their total purchase amount, and their preferred free sample.

Actions are the outcomes that occur based on the conditions. Let’s add a few relevant actions.

In the top toolbar, click Add Action.
A dialog will appear for you to name the action. In the Name field, type Apply 15% Discount and click OK.
Repeat this process to add two more actions:

Now your table contains the actions that will be triggered depending on the conditions you set.

Rules are where you specify how the conditions and actions interact. Let's set up three rules.

In the first rule column, in the Is the customer a premium member? row, check the box to indicate Yes.
In the Total purchase amount row, enter 100 and select the '>=' operator from the dropdown.
In the Preferred free sample row, choose Apple from the dropdown.
In the actions section, check all three boxes: Apply 15% Discount, Offer Free Shipping, and Add Preferred Free Sample to Cart.

For the second rule, leave the premium member box unchecked.
In the Total purchase amount row, enter 200 and select '>='.
Choose Banana for the Preferred free sample.
Check the actions for Offer Free Shipping and Add Preferred Free Sample to Cart.

For the third rule, leave the premium member box unchecked.
In the Total purchase amount row, enter 100 and select '<' operator.
Choose Cherry for Preferred free sample.
Check only the action Add Preferred Free Sample to Cart.

Now you've defined three rules that dictate how the conditions lead to actions. Each rule specifies a unique scenario and its corresponding outcomes.

With your decision table complete, you can now save or export it.

Export to CSV: You can export the decision table as a CSV file by clicking the Export button in from the toolbar.
Print: If you prefer, print the table directly from the application.
Switch to Diagram View: You can also switch to a visual diagram view by clicking the Diagram tab at the bottom of the workspace. In this view, you can adjust the size and appearance of the table.
Export as Image: To export the table as an image, right-click on the diagram canvas and select Export Diagram.... You can choose from a variety of image formats for export.