Creating a business rule

You use the rule editor to create and work with rules and use the special facilities provided.

About this task

A business rule defines the specific actions to take when certain conditions are met. A basic rule uses an if-then statement to associate a condition (if) with an action (then).

Procedure

  1. Use one of the following options to create the rule:
    Option Procedure
    Create a rule at the root of the task model In the task model toolbar, click the Add business rule button Add business rule button.
    Create a rule inside a folder or subfolder
    1. Open the folder.
    2. Click the + button, and select New business rule.
  2. Click the default name of the rule to update it.
  3. Start building the different parts of the rule. You can:

    • Type directly in the editing area.

    • Copy text from another editor or application, and paste it into the editing area.

    • Select predefined terms and phrases from a completion menu.

Results

You can now use the rule editor to complete the different parts of your rule.

For more information about how to build rules, see Working with business rules. The rule language reference manual is available in the Rule language section.

Example

For example, consider a decision that gives a discount that depends on the category of a customer and how much the spent.

When you create a rule, the rule template contains a simple expression, with the construct if <condition> then <action>. You can generate a rule that is closer to the decision logic that you want to express by selecting the input data that the rule needs to make the decision. Here the input data is the customer category and the value of the shopping cart of the customer. When they are selected in the list of criteria, an if part with conditions that use these inputs is added to the rule template.

The conditions contain placeholders where you will indicate actual values. The types of these values and the default constructs depend on the type of data that you defined in your data model and on the node types in the diagram.

Similarly, the output of the decision is the amount of the discount. Therefore, the placeholder for the value of the decision indicates that is a number, based on the output type of the decision.

Now, let's say that the actual decision logic consists in giving a discount of 10 to Gold customer whose cart value is over 100. In the rule editor, the rule template can be modified to represent this decision logic. In the following example, the construct to evaluate the shopping cart value has been replaced with one that is more relevant to this case, and the placeholders for the shopping cart, category, and discount values have been filled with specific values.

if
   'shopping cart value' is more than 100
   and 'customer category' is "Gold"
then
   set 'discount' to 10;