Configure decision tables

You can build and refine decision logic by adding inputs, outputs, and rules to your tables. You initiate a table from the Design tab and then define its specific logic — including Hit Policies and Data Types — within the Logic tab.

Create a decision table

Decision and Business Knowledge Model elements support decision tables. Tables are created in the Logic tab with a default input and output. You can add multiple inputs and outputs to the table.

You create decision tables in the Design tab.

1. In the diagram, select a Decision or a Business Knowledge Model component.

2. In the right-menu of the Ring, click .

The element now displays a decision table marker.

Define inputs

Inputs are represented as columns. Every input can have multiple input entries.

You define an input in the Attributes panel.

To define an input:

1. Select an input in the table.

2. In the Configuration panel, open Attributes.

3. Define the input by completing these attribute fields:

Define outputs

Outputs are represented as columns. Outputs can have several output entries.

You define an output in the Attributes panel.

To define an output:

1. Select an output in the table.

2. In the Configuration panel, open Attributes.

3. Define the output by completing these attribute fields:

Add inputs and outputs

New inputs are added in the last Input column of the table. New outputs are added in the last Output column of the table.

If you’ve selected an existing input/output in the table, you’ll be give the option to add the new input/output to the right or left of the selected input/output.

To add an input or output to the decision table:

1. In the toolbar, click Add Input or Add Output.

2. Define the input/output in the Attributes panel.

Move inputs and outputs

You can change the order in which inputs and outputs appear in the column by moving them left or right.

• In the toolbar, click Move Input or Move Output, then select Left or Right.

Delete inputs and outputs

1. Select the input/output you want to delete.

2. In the toolbar, click Delete Input or Delete Output.

Specify rules

Rules are expressed as rows within a table. Generally, a decision table will consist of multiple rules with every rule consisting of one or more input entries and a corresponding output entry.

Add a rule for each possible scenario of an input and output. The end result will be a decision table with all the relevant scenarios for the decision logic.

You can use FEEL expressions or any defined data type as entries. Make sure that the type of values you include is consistent with the data type of the input/output.

When you add a rule a new row is added at the bottom of the table. If you’ve selected a rule in the table, you’ll be given the option to add the new rule above or below the selected rule.

To add a rule:

1. In the toolbar, click Add Decision Rule.

2. In the Configuration panel, open Attributes.

3. Define the input and output entries by completing these fields:

Move a rule

You can change the order in which rules appear in the table by moving them up or down.

• In the toolbar, click Move Rule, then select Up or Down.

Delete a rule

1. Select the rule you want to remove.

2. In the toolbar, click Delete Rule.

Define a Hit Policy

A decision table usually has several rules. If these rules overlap — more than one rule matches a given set of input values — a hit policy selects the proper output value. The output value can be a single value or a list of values.

There are two types of hit policies: Single Hit and Multiple Hit.

Single hit policies produce one result per input. Only one rule is applied at a time, even if several rules exist.

Multiple hit policies produce a list of outputs. All applicable rules are considered regardless of their position in the table. The resulting output can be a list or aggregated to a single value.

These are the hit policies:

Define the Hit Policy

1. In the Configuration panel, click Attributes.

2. In Hit Policy, click and select the policy from the dropdown list.

View the logic list

The logic list enables you to explore all the decision tables in a model. The list is divided into two sections — Decisions and Business Knowledge Models.

To view the logic list:

• In the Configuration panel, click Logic List.

Delete a Decision Table

1. In the Design tab, select the Decision or a Business Knowledge Model element displaying the icon, and in the right-menu of the Ring, click .

2. In the dialog box that opens, click Delete.