Business rules

Text-based business rules

A text-based business rule consists of the following elements:

Definitions

The optional definitions part of the rule specifies variables that can be used in the rule. The scope of these variables is limited to the specific rule in which the variables are defined.

Conditions

The if part of the rule specifies the circumstances in which the actions in the then and else parts of a rule are to be carried out.

Restriction: You can use the following system properties in business rule conditions, but you cannot include them in business rule actions to set their values:

• Case Identifier
• Creator
• Date Created
• Date Last Modified
• Last Modifier
• Case State

Actions

The then part of the rule specifies the actions to take if the conditions are true. The optional else part of the rule specifies actions to take if the conditions in the if part are false.

Tip: For troubleshooting purposes, you can specify one or more print actions in a rule so that the associated rule step returns the specified strings to the workflow. The return value of the rule step can then be mapped to a data field that can be used by the next step in the workflow.

For example, for a loan case type, you can define a rule to set the value of the Interest_Rate case property to 3.5% if the credit rating of the applicant is higher than 700. In the following examples, Credit_Rating is a custom rule parameter. (The following examples are written in the English locale.)

if Credit_Rating is more than 700 
then set the Interest_Rate of LoanCaseType to 3.5; 

Table-based business rules

A table-based rule, also known as a decision table, consists of condition and action columns. Each condition column specifies the circumstance for which particular actions are to be carried out. Each action column specifies the actions to take if the conditions are true. Each row in the table represents a separate rule. If the conditions of a row are met, the actions in that row are taken.

For example, you want to create a group of rules that sets the value of the Interest_Rate case property for different ranges of credit rating values. You first define a condition column that represents the value of the Credit_Rating custom rule parameter for a loan applicant.

Credit_Rating is <a number>

Next, you define an action column that represents the interest rate to offer:

set the Interest_Rate of LoanCaseType to <a number>

Then, in each row, you specify a particular credit rating and the corresponding interest rate:

As you specify values in each row, Case Builder by default checks that the values that you enter for a given condition do not overlap or are not identical. For example, consider a column for the age of the customer:

• Row 1: age is between 17 and 30
• Row 2: age is between 29 and 40

In this example, customers that are 29 years old satisfy the condition of both rows. Case Builder reports this as an overlap warning.

By default, Case Builder also checks that the cells in a condition column consider all possible cases, which helps you ensure that there are no gaps in your table. For example, consider a column for the age of the customer:

• Row 1: age is between 17 and 30
• Row 2: age is between 32 and 40

In this example, customers that are 31 years old are not taken into account. Case Builder reports this as a gap warning.

Defining preconditions in table-based rules

For table-based rules, you can use preconditions to check incoming data to determine whether the table-based rule can process the information. You can also use preconditions to define variables that can be used in the rule. The scope of these variables is limited to the specific rule in which the variables are defined.

Checking for null values

To avoid receiving possible errors during run time, use defensive programming techniques to ensure that values are populated for all case properties whose values are retrieved in a business rule.

Use the definitions section in a rule to declare variables for all case properties whose values are retrieved. If a case property is not initialized, its variable is not initialized and the rule is not run.

definitions
 set balanceAmount to the Opening_Balance of Account_Request;

if balanceAmount is more than 10000 
then set the Interest_Rate of Account_Request to 0.55;   

Defining temporary variables

You can define temporary variable in the definitions section to calculate intermediary values that can be used in a rule. For example, you define a business rule to set the value of the ProfitAfterTax case property. Because no case property corresponds to the profits before tax, you define an intermediary ProfitBeforeTax variable to calculate the profits before tax according to the values of the Assets and Liabilities case properties. To determine the correct tax rate, you add a condition in the rule to use a higher tax rate if the profits are more than 1 million dollars.

definitions  
	set ProfitBeforeTax to 
	(the Assets of TaxCasetype - the Liabilities of TaxCasetype);
	set Tax to .07;
	set SurchargeForHigherIncome to .005;

if ProfitBeforeTax is more than 1000000 
then set the ProfitAfterTax of TaxCaseType to 
	(ProfitBeforeTax - ProfitBeforeTax *(Tax+SurchargeForHigherIncome)) ;
else set the ProfitAfterTax of TaxCaseType to 
	(ProfitBeforeTax -ProfitBeforeTax*Tax);

Using Boolean properties in business rules

The following examples show how you include Boolean properties in a rule.

• If the value of a Boolean property is true, set the value of another Boolean property to false:

  if CaseTypeName is BooleanProperty1
  then make it false that CaseTypeName is BooleanProperty2

• If the value of a Boolean property is false, set the value of another Boolean property to true:

  if it is not true thatCaseTypeName is BooleanProperty1
  then make it true that CaseTypeName is BooleanProperty2

For more information about defining rules, see the Business Rules Embedded documentation.