Columns

Each column in a decision table represents a condition or an action. The column header identifies an object that is tested in a condition or the target of an action.

The columns of a decision table define the conditions and actions that apply to the rules contained in the table. Typically, the condition columns are unshaded, and action columns are shaded.

	Grade	Amount of loan		Insurance required	Insurance rate
	Grade	Min	Max	Insurance required	Insurance rate
1	A	<100,000		false
2	A	100,000	300,000	true	0.001

Each row in the table corresponds to one rule. The actions of a rule are performed when all of its conditions are valid. For example, the rule corresponding to the second row in the figure reads as follows:

if
   all of the following conditions are true:
      - the loan grade is A
      - the amount of the loan is between 100000 and 300000
then
   set the Insurance required to true
   set the Insurance rate to 0.001

Split columns

Conditions can be split across more than one column of the table when the rule statement they represent contains more than one value. For example, the following condition requires you to specify a value for both <min> and <max>.

if
   the age of the customer is between <min> and <max>

In a decision table, this condition is represented in the Age column, but across two subcolumns: one for the value <min> and one for the value <max>:

	Age
	Min	Max
1	18	25
2	26	40