Walkthrough: Creating a Decision Table

This walkthrough presents the following fundamental procedures for creating a decision table with ILOG Rule Studio for .NET:

In this walkthrough you create a console application that uses a decision table to select a message to display in a command window.

Setting up the Business Rule Application

Setting up the application involves creating a solution and defining the classes that model the items of interest in the business domain. You import these classes into the business object model so that you can use them to write rules.

To set up the business rule application

The Message class:

using System;
namespace ClassLibrary1{  
  // Class to print a message
  public class Message
  {
    // Prints a message to the console
    public void PrintMessage(string msg)
    {
      Console.WriteLine(msg);
    }
  }
}
Imports System
' Class to print a message
Public Class Message
    ' Prints a message to the console
    Public Sub PrintMessage(ByVal msg As String)
        Console.WriteLine(msg)
    End Sub
End Class

The Customer class:

using System;
namespace ClassLibrary1{
  //A class for holding customer information
  public class Customer
  {
      //Constructor
    public Customer(int age, bool hasAccount)
    {
      this.age = age;
      this.hasAccount = hasAccount;
    }
 
    // The age of the customer
    private int age;
    public int Age 
    {
      get { return age; }
    }
 
    // Test if the customer has an account.
    private bool hasAccount;
    public bool HasAccount
    {
      get { return hasAccount; }
    }
  }
}
Imports System
' A class for holding customer information
Public Class Customer
    Private m_age As Integer
    Private m_hasAccount As Boolean
 
    'Constructor
    Public Sub New(ByVal age As Integer, ByVal hasAccount As Boolean)
        Me.m_age = age
        Me.m_hasAccount = hasAccount
    End Sub
    'The age of the customer
    Public Property Age() As Integer
        Get
            Return m_age
        End Get
        Set(ByVal Value As Integer)
            m_age = Value
        End Set
    End Property
    'Test if the customer has an account
    Public Property HasAccount() As Boolean
        Get
            Return m_hasAccount
        End Get
        Set(ByVal Value As Boolean)
            m_hasAccount = Value
        End Set
    End Property
End Class

Creating the Decision Table

To create the decision table you:

To define the rule project

To create the decision table

Now the decision table is ready to be populated.

To populate the decision table

Now the table is populated, however, you still need to consider the cases for customers that have accounts with ages less than 18 and more than 65. You can also make the table a little easier to read by removing the unwanted cells and adjusting the alignment of the text.

To complete the decision table

The final decision table should now look something like this:

Defining the Application Logic

To define the application logic you:

To define the application project

To implement the application logic

using System;
using System.IO;
using ILOG.Rules;
using ClassLibrary1;
namespace ConsoleApplication1 {  
  public class RuleExecuter {    
    public static void Main() {      
      // Create a rule engine in which to execute the ruleset.
      RuleEngine engine = new RuleEngine();
 
      // The message containing the promotion information.
      Message promotion = new Message();
 
      // The customers to be considered.
      Customer jack = new Customer(72, true);
      Customer nandira = new Customer(16, false);
      Customer laurel = new Customer(45, true);
      Customer felix = new Customer(23, true);
 
      // Add objects to the rule engine's working memory.
      engine.Assert(promotion);
      engine.Assert(jack);
      engine.Assert(nandira);
      engine.Assert(laurel);
      engine.Assert(felix);
            
      // Load the ruleset into the rule engine.
      engine.RuleSet = new BusinessRules1(); 
 
      // Execute the ruleset.
      engine.Execute();
 
      //Get the user's input to quit the application.
      Console.WriteLine();
      Console.WriteLine("To exit, press ENTER.");
      Console.In.ReadLine();
    }  
  }
}
Imports System
Imports System.IO
Imports ClassLibrary1
Imports ILOG.Rules
Module Module1
 
    Sub Main()
        ' Create a rule engine in which to execute the ruleset.
        Dim engine As New RuleEngine
        ' Load the ruleset into the rule engine.
        engine.RuleSet = New BusinessRules1
 
        ' The message containing the promotion information.
        Dim promotion As New Message
 
        ' The customers to be considered.
        Dim jack As New Customer(72, True)
        Dim nandira As New Customer(16, False)
        Dim laurel As New Customer(45, True)
        Dim felix As New Customer(23, False)
 
        ' Add objects to the rule engine's working memory.
        engine.Assert(promotion)
        engine.Assert(jack)
        engine.Assert(nandira)
        engine.Assert(laurel)
        engine.Assert(felix)
 
        ' Execute the ruleset.
        engine.Execute()
 
        ' Get the user's input to quit the application.
        Console.WriteLine()
        Console.WriteLine("Press ENTER to exit.")
        Console.In.ReadLine()
    End Sub
 
End Module

Running the Business Rule Application

You can test the business rule application within Visual Studio.

To run the business rule application