Pega Test Topics

Decision Rules of Exam 6

Decision Rule Types

ndash Describe the following types of decision rules and their function

1048696 Decision Tables

1048696 Decision Trees

1048696 Map Values

1048696 When Conditions

ndash Compare different decision rule types and identify when to use them Exam Blueprint 11 Fork and Decision Shapes Explain the difference between fork shapes and decision shapes in a flow

DefinitionA decision rule is usually called from a flow and is used to make a decision about the path the flow should take It can also be called from a declarative rule

A Decision table contains one or more rows each containing test conditions and a result to return Evaluation proceeds top-down When all cells are true for a row the result of that row is returned If no row is true the table returns the Otherwise rowrsquos result Empty cell defaults to a true Decision tables are instances of the Rule-Declare-DecisionTable class

A decision tree uses ifthen logic to return a value based on rows of property values and computations (including comparisons) It is an instance of Rule-Declare-DecisionTree class

A Map value rule is a rule that converts one or two input values to a calculated result value using a matrix to look up the result Map values can be cascaded ndash one map value calls another which calls a third etc Thus an output can be decided based on more than 2 inputs Map value rules can be called from a flow another map value an activity (using a Property-Map-Value method) a declare expression They are instances of the Rule-Obj-MapValue rule type

A When Condition rule defines a true-false test based on comparing one or more property values with constants or other property values It is an instance of the Rule-Obj-When rule type

When to use what

1 Use map values when you need to make decisions based on ranges of one or two inputs Note map value rules can be cascaded

2 Use decision table when the tests are based on the same set of properties and data is easy to see in a tabular form

3 Use decision tree when the tests tend to be for different properties and the conditions are complex (like nested ifthenelse conditions)

4 Use When rules when you want a truefalse test result

Fork and Decision Shapes

1 Use fork when you use a when rule to make the decision2 Use a decision shape when you use a decision tree or decision table to make the

decision

A When Condition rule defines a true-false test based on comparing one or more property values with constants or other property values It is an instance of the Rule-Obj-When rule type

When to use what

1 Use map values when you need to make decisions based on ranges of one or two inputs Note map value rules can be cascaded

2 Use decision table when the tests are based on the same set of properties and data is easy to see in a tabular form

3 Use decision tree when the tests tend to be for different properties and the conditions are complex (like nested ifthenelse conditions)

4 Use When rules when you want a truefalse test result

Fork and Decision Shapes

1 Use fork when you use a when rule to make the decision2 Use a decision shape when you use a decision tree or decision table to make the

decision