A Decision Table displays multiple related rules in a single spreadsheet-style view. In Rules Designer a Decision Table presents a collection of related business rules with condition rows, rules, and actions presented in a tabular form that is easy to understand. Business users can compare cells and their values at a glance and can use Decision Table rule analysis features by clicking buttons and selecting values in Rules Designer to help identify and correct conflicting or missing rules.

To help understand Decision Table concepts, consider a set of IF/THEN rules that determines if a driver is eligible for a license, and an equivalent Decision Table. Note if a driver has taken a driver training class then the driver has training certification.

The IF/THEN rules follow:

if driver.age < 20 and driver.has_training then training = true
if driver.age < 20 and driver.has_training = false then driver.eligible = false
if driver.age >= 20 then driver.eligible = true (do not care about training for this case) 

Figure 5-1 shows a Decision Table representation of these rules that includes areas for Decision Table Conditions and Actions.

Figure 5-1 Sample Decision Table with Conditions and Actions

Description of "Figure 5-1 Sample Decision Table with Conditions and Actions"

By default, when you create a condition row, Rules Designer creates a single condition cell and assigns the "?" value to the cell. A condition cell with the value "?" indicates that the value of the cell is undefined in the value set. For example, Figure 5-5 shows a "?" value for StrategyContext. Note that contiguous value ranges in a condition cell are combined. For example, if you select <20 and [20..40] it will display as <=40.

Figure 5-5 Sample Decision Table Showing Undefined in Condition Cell

Description of "Figure 5-5 Sample Decision Table Showing Undefined in Condition Cell"

In the Decision Table Actions area you can specify that an action cell "do nothing." In this case, clear the action cell. When the action cell check box is cleared, this means do not perform this action when the pattern matches for the specified condition values in the Decision Table. Thus, for each action cell you can specify whether the rule associated with the action cell should activate the action, or does not perform the action.

In a Decision Table, when a condition cell represents a value that has been removed from the value set, Rules Designer provides a validation warning such as the following:

RUL-05831: Decision table value reference not found

To fix this type of validation warning you can do one of the following:

• Define a value by double-clicking the condition cell and selecting one or more values from the list.

• Add the missing value to the value set or associate the condition with another value set that contains the missing value.

1. From Rules Designer select an existing ruleset from the rulesets tab or create a ruleset by clicking Create Rule Set....
2. Click Create from the Decision Tables area on the Overview tab, as shown in Figure 5-6. This creates a Decision Table.

   Figure 5-6 Adding a Decision Table

   
   Description of "Figure 5-6 Adding a Decision Table"

1. From Rules Designer select a ruleset from the Rulesets navigation tab and select the Decision Table where you want to add conditions.
2. In the Decision Table area, from the list next to the Add button select Condition.
3. In the Conditions area, double-click <edit-condition> to display the navigator to select or enter an expression as shown in Figure 5-7.

   Figure 5-7 Adding a Condition to a Decision Table

   
   Description of "Figure 5-7 Adding a Condition to a Decision Table"
4. Enter an expression by clicking in the navigator to select a variable or click the Expression Builder button to display the Expression Builder window. The Expression Builder lets you build expressions.
5. Each condition row requires a value set from which to draw the values for each cell. When the value you select has an associated global value set, then by default the value set is associated with the condition row.
6. Repeat Step 2 through Step 5, as required to add additional condition rows in the Decision Table.

1. Each condition row requires a value set from which to draw the values for each cell. When the value you select has an associated global value set, then by default the value set is associated with the condition row.
2. If there is no global value set associated with the value, then after you add a condition row to a Decision Table you need to specify either a Local List of Values or a Local List of Ranges value set to associate with the condition row, or specify an existing global value set. To add a value set for the condition, in the Conditions area select the condition and then select from the value set list to associate a value set, as shown in Figure 5-8. The value set list includes available global value sets of the appropriate type.

   Figure 5-8 Specifying a Value Set For a Condition Row in a Decision Table

   
   Description of "Figure 5-8 Specifying a Value Set For a Condition Row in a Decision Table"
3. If you do not specify a global value set, then you can create and use a local value set by selecting either Local Value Set or Local Range Value Set to create and use the specified type of value set.
4. Repeat Step 2 through Step 3, as required to define additional condition rows in the Decision Table.

1. From Rules Designer select a ruleset from the Rulesets navigation tab and select the Decision Table where you want to add actions.
2. From the list next to the Add button, select Action and select an available action from the list. Table 5-1 lists the available actions. For example, select Modify. Rules Designer displays the Action Editor dialog as shown in Figure 5-9.

   Figure 5-9 Adding an Action to a Decision Table

   
   Description of "Figure 5-9 Adding an Action to a Decision Table"
3. In the Action Editor dialog select the action target in the Target area. This specifies the data model object the action applies to.
4. For the specified target, as needed to make the action do what is required, modify the fields in the Arguments table. In the Action Editor dialog the Arguments table includes the fields shown in Table 5-2.

   Table 5-2 Action Editor Dialog Arguments Fields

   Field	Description
   Property	Displays the property names for the specified target.
   Type	Displays the type for the property.
   Value	Select the default value for the action from the list of available actions. The specified value applies to either the entire action, as the default value, or when a particular action cell is selected, the value specified applies for that particular action cell.
   Parameterized	This specifies a parameterized value. A parameterized value displays in a Decision Table action cell. When you select parameterized value for a property, this generally means that each rule supplies a different parameter value.
   Constant	Select to specify a constant value.

5. In the Action Editor dialog, to select action cells for all the rules, select the Always Selected check box.
6. Repeat Step 2 through Step 5, as required to define additional actions for the Decision Table.

1. From Rules Designer select a ruleset from the Rulesets navigation tab and select the Decision Table where you want to add the rule.
2. From the list next to the Add button, select Rule.
3. Enter values for the condition cells. Notice that the new rule is added as the first rule of the Decision Table on the left and the other rules have moved as required to keep the values in their defined order.
4. Enter values for the action cells.

1. From Rules Designer, select a ruleset from the Rulesets navigation tab and select the Decision Table where you want to add the rule.
2. Click the Show Patterns/Tests button (magnifying glass) left of the Decision Table name. If Advanced Mode is selected, clear the check box.
3. Select any of the options according to your requirements, as shown in Figure 5-10. Note that variables without any tests are often used so that the variables can be used in the decision table conditions and actions.

   • simple test

   • variable

   • nested test

   • negated test

   • all of the following...

   • any of the following...

   • is a

   • there is a fact where...

   • there is a case where...

   • there is no fact where...

   • there is no case where...

   • aggregation...

   • boolean expression

   Figure 5-10 Options List

   
   Description of "Figure 5-10 Options List"
4. Click the left and the right <operand> to enter the operand values, and the operator list to select an operator, as in Figure 5-11:

   Figure 5-11 Value Options List

   
   Description of "Figure 5-11 Value Options List"

The split and compact operations enable you to manipulate the contents of the condition cells in a Decision Table.

The split table operation creates a rule for every combination of values across the conditions. For example, in a Decision Table with 3 boolean conditions, 2 x 2 x 2 = 8 rules are created. In a Decision Table with 32 boolean conditions, 2**32 ~ 2 billion rules are created. Thus, you only use split table when the number of rules created is small enough that filling in the action cells is feasible.

When you want to apply match conditions for the "do not care" values in a Decision Table and create a match case for each cell, you use the split table operation.

Split can be applied to an entire Decision Table or to a single condition row. Additionally, split may be performed on an individual condition cell.

Depending on what is selected in the Decision Table, the split operation can create condition cells. Thus, using the split operation you can create rules in a Decision Table. Table 5-3 summarizes the split operation for a selected condition cell, condition row, or for a complete Decision Table.

Depending on what is selected in the Decision Table, the compact table or merge cells operations remove condition cells. The compact table operation can be applied to an entire Decision Table. Additionally, the merge operation may be performed on sibling cells or on an entire condition row. Thus, using compact table or merge you can remove rules from a Decision Table. Table 5-4 summarizes the compact table and merge operations.

Split and merge are inverse operations when conflicting action cells are not associated with the operation. In this case, without conflicting action cells, a merge operation combines all the values from the siblings into one sibling, and discards the other sibling condition cells, and as a result of merging the condition cells, when a Decision Table contains action cells, the action cells are also merged. Thus, the merge operation combines multiple condition cells into a single condition cell and adds all values to the single cell.

When there are conflicting values for the action cells, a merge operation merges the action cells in a form that requires additional manual steps. Thus, if two action cells have conflicting parameters, after the merge the action cell contains multiple conflicting parameter values. These conflicting values are appended to the action cell and must be manually resolved by selecting and deleting the unwanted duplicate parameters. For example, see Figure 5-12 that shows conflicting values in an action cell.

An action cell that contains multiple values for a property is invalid. When you select the action cell Rules Designer shows a popup window with check boxes to allow you to select a single value for the action cell. As shown in the validation log in Figure 5-12, Rules Designer shows a validation warning until you select a single value.

Figure 5-12 Conflicting Properties to be Resolved for a Merged Action Cell

Description of "Figure 5-12 Conflicting Properties to be Resolved for a Merged Action Cell"

1. In Rules Designer, select a rule set from the Rule Sets navigation tab. On the Overview tab, select the Decision Table and click Edit.
2. Click the Compact Table button to compact or the Split Table button to split the cells.

1. In Rules Designer, select a rule set from the Rule Sets navigation tab. On the Overview tab, select the Decision Table where you want to merge or split a condition and click Edit.
2. In the Conditions area, select the condition you want to merge or split.
3. Right-click, and from the list select Merge Condition or Split Condition.

1. In Rules Designer, select a rule set from the Rule Sets navigation tab. On the Overview tab, and select the Decision Table where you want to perform gap checking and click Edit.
2. Click the Gap Analysis button.

1. In Rules Designer, select a rule set from the Rule Sets navigation tab. On the Overview tab, and select the Decision Table where you want to check conflicts and click Edit.
2. Set the conflict policy to manual (this is the default conflict policy). For more information, see Understanding Decision Table Conflict Analysis.
3. In the Conditions area, in the conflicts area, when conflicts exist for each rule with a conflict double-click the appropriate condition cell to display the Conflict Resolution dialog.
4. In the Conflict Resolution dialog, for each conflicting rule, in the Resolution field select a resolution from the list.

1. Select the rule or Decision Table where you want to use ignore conflict policy.
2. Click the Show Advanced Settings button next to the rule or Decision Table name.
3. From the Conflict Policy option select auto override.

1. Select the rule or Decision Table where you want to use the ignore conflicts policy.
2. Click the Show Advanced Settings button next to the rule or Decision Table name.
3. From the Conflict Policy option select ignore.

The source code for Oracle Business Rules-specific samples and SOA samples are available online in the Oracle SOA Suite Samples and Tutorials page.

To work with the Order Approval application, you first need to obtain the order.xsd schema file either from the sample project that you obtain online or you can create the schema file and create all the application, project, and other files in Oracle JDeveloper. You can save the schema file provided in the following example locally to make it available to Oracle JDeveloper.

The following example shows the order.xsd schema file.

<?xml version="1.0" ?>
<schema attributeFormDefault="qualified" elementFormDefault="qualified"
        targetNamespace="http://example.com/ns/customerorder"
        xmlns:tns="http://example.com/ns/customerorder"
        xmlns="http://www.w3.org/2001/XMLSchema">
  <element name="CustomerOrder">
    <complexType>
      <sequence>
        <element name="name" type="string" />
        <element name="creditScore" type="int" />
        <element name="annualSpending" type="double" />
        <element name="value" type="string" />
        <element name="order" type="double" />
      </sequence>
    </complexType>
  </element>
  <element name="OrderApproval">
    <complexType>
      <sequence>
        <element name="status" type="tns:Status"/>
      </sequence>
    </complexType>
  </element>
  <simpleType name="Status">
    <restriction base="string">
        <enumeration value="manual"/>
        <enumeration value="approved"/>
        <enumeration value="rejected"/>
    </restriction>
  </simpleType>
 </schema>

1. In the Application Navigator, in the OrderApproval project expand SOA Content and double-click composite.xml to launch the SOA composite editor (this may already be open after you create the project).
2. From the Component Palette, drag-and-drop a Business Rule from the Service Components area of the SOA menu to the Components lane of the composite.xml editor.

   Oracle JDeveloper displays a Create Business Rules page, as shown in Figure 5-22.

   Figure 5-22 Adding a Business Rule Dictionary with the Create Business Rules Dialog

   
   Description of "Figure 5-22 Adding a Business Rule Dictionary with the Create Business Rules Dialog "
3. To add an input, from the list next to the Add button select Input to enter input for the business rule.
4. In the Type Chooser dialog, click the Import Schema File... button. This displays the Import Schema File dialog.
5. In the Import Schema dialog click Browse Resources to choose the XML schema elements for the input variable of the process. This displays the SOA Resource Lookup dialog.
6. In the SOA Resource Lookup dialog, navigate to find the order.xsd schema file and click OK.
7. In the Import Schema File dialog, make sure Copy to Project is selected, as shown in Figure 5-23. Click OK.

   Figure 5-23 Importing the Order.xsd Schema File

   
   Description of "Figure 5-23 Importing the Order.xsd Schema File"
8. If the Localize Files dialog displays, click OK to copy the schema to the composite process directory.
9. In the Type Chooser, navigate to the Project Schemas Files folder to select the input variable.

   For this example, select CustomerOrder as the input variable.

   On the Type Chooser window, click OK. This displays the Create Business Rules dialog, as shown in Figure 5-24.

   Figure 5-24 Create Business Rules Dialog with CustomerOrder Input

   
   Description of "Figure 5-24 Create Business Rules Dialog with CustomerOrder Input"
10. In a similar manner, add the output fact type OrderApproval from the imported order.xsd.
11. In the Create Business Rules dialog, select Expose as Composite Service, as shown in Figure 5-25.

    Figure 5-25 Create Business Rules Dialog with Input and OrderApproval Output

    
    Description of "Figure 5-25 Create Business Rules Dialog with Input and OrderApproval Output"

    Click OK. This creates the Business Rule component and Oracle JDeveloper shows the Business Rule in the canvas workspace, as shown in Figure 5-26.

    Figure 5-26 Business Rules Component in OrderApproval Composite

    
    Description of "Figure 5-26 Business Rules Component in OrderApproval Composite"

1. Select the composite tab with the value composite.xml, and in the Components lane select the business rule (this surrounds the component, OracleRules1 with a dashed selection box).
2. Double-click the selection box to launch Rules Designer.
3. In Rules Designer select the Facts navigation tab.
4. Select XML Facts tab in the Facts navigation tab as shown in Figure 5-27.

   Figure 5-27 Opening a Business Rules Dictionary with Rules Designer

   
   Description of "Figure 5-27 Opening a Business Rules Dictionary with Rules Designer"

1. In Rules Designer, select the Value Sets navigation tab.
2. From the drop down next to the Create Value Set... button, select Range Value Set.
3. In the Name field, enter OrderAmount. Press Enter to accept the name.
4. Double-click the OrderAmount value set icon to display the Edit Range Value Set dialog.
5. Click Add Value to add a value.
6. Click Add Value again to add another value.
7. In the Range Values area, in the top Endpoint field enter 1000 for the endpoint value.
8. In the Range Values area, for the middle bucket in the Endpoint field enter 500 for the endpoint value.
9. In the Included Endpoint field for each value set ensure the check box is selected, as shown in Figure 5-28.

   Figure 5-28 Adding the OrderAmount Value Set

   
   Description of "Figure 5-28 Adding the OrderAmount Value Set"
10. Modify the Alias field for each value to High, Medium, and Low. Click OK.

1. In Rules Designer select the Facts navigation tab.
2. Select the XML Facts tab in the Facts navigation tab as shown in Figure 5-29.

   Figure 5-29 Opening a Business Rules Dictionary with Rules Designer

   
   Description of "Figure 5-29 Opening a Business Rules Dictionary with Rules Designer"
3. Select the type you want to modify. For example in the XML Facts table double-click the icon next to the CustomerOrder entry. This displays the Edit XML Fact dialog.
4. In the Edit XML Fact dialog, in the Properties table in the Value Set column select the cell for the appropriate property and from the list select the valueset you want to use. For example, for the property order select the OrderAmount valueset, as shown in Figure 5-30.

   Figure 5-30 Associating the OrderAmount Valueset with CustomerOrder.order

   
   Description of "Figure 5-30 Associating the OrderAmount Valueset with CustomerOrder.order"
5. In a similar manner, for the property creditScore select the CreditScore valueset.
6. Click OK.

1. In Rules Designer, select Ruleset_1 under the Rulesets navigation tab.
2. Click the Add button and from the list and select Create Decision Table.
3. In the Decision Table, click the Add button and from the list select Condition.
4. In the Decision Table, double-click <edit condition>. Then, in the navigator expand CustomerOrder and select creditScore. This enters the expression CustomerOrder.creditScore in the Conditions column.
5. Again, in the Decision Table, click the Add button and from the list select Condition.
6. In the Decision Table, in the Conditions area double-click the <edit condition>. Then, in the navigator expand CustomerOrder and select order. This enters the expression CustomerOrder.order.
7. Again, in the Decision Table, click the Add button and from the list select Condition.
8. In the Decision Table, double-click <edit condition>.
9. In the navigator expand CustomerOrder and select annualSpending. In the text entry area, add >2000 as shown in Figure 5-31.

   Figure 5-31 Adding the Annual Spending Entry to a Decision Table

   
   Description of "Figure 5-31 Adding the Annual Spending Entry to a Decision Table"
10. Type Enter to accept the value, as shown in Figure 5-32. If you view the rules validation log you should see the warning messages as shown in Figure 5-32. You remove these warning messages as you modify the Decision Table in later steps.

    Figure 5-32 Adding Conditions to the CustomerOrder Decision Table

    
    Description of "Figure 5-32 Adding Conditions to the CustomerOrder Decision Table"

Before you can deploy the application you need to make sure the dictionary validates without warnings. If there are any validation warnings, you need to fix any associated problems. To validate the dictionary, in the Business Rule Validation Log, check for any validation warnings. If there are warnings, perform appropriate actions to correct the problems.

1. If you have not started your application server instance, then start the Oracle WebLogic Server.
2. In the Application Navigator, right-click the OrderApproval project and select Deploy > OrderApproval > to the appropriate server name.

   Then the SOA Deployment Configuration dialog displays. Select your Application connection which you either have created already or you can create it now. The connection contains the authorization and other connection information (server name, port, etc).

3. Click Next.
4. In Select Server select or create and then select your application connection.
5. Click Next, Next and Finish.

1. Open the composite application in Oracle Enterprise Manager Fusion Middleware Control Console, as shown in Figure 5-42.

   Figure 5-42 Testing the Order Approval Application

   
   Description of "Figure 5-42 Testing the Order Approval Application"
2. Click Test.
3. In the Input Arguments area, select XML View. Replace the XML with the contents of the sample input for testing Order Approval application example as shown below.

   <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
      <soap:Body xmlns:ns1="http://xmlns.oracle.com/OracleRules1/OracleRules1_DecisionService_1">
           <ns1:callFunctionStateless name="OracleRules1_DecisionService_1">
                      <ns1:parameterList xmlns:ns3="http://example.com/ns/customerorder">
                              <ns3:CustomerOrder>
                                      <ns3:name>Gary</ns3:name>
                                          <ns3:creditScore>600</ns3:creditScore>
                                          <ns3:annualSpending>2001.0</ns3:annualSpending>
                                          <ns3:value>High</ns3:value>
                                          <ns3:order>100.0</ns3:order>
                       </ns3:CustomerOrder>
                      </ns1:parameterList>
              </ns1:callFunctionStateless>
          </soap:Body>
   </soap:Envelope> 
   

4. Replace the values in the input shown in step 3 as desired for your test.
5. Click Test Web Service.
6. In the Response tab, view the results. For example, for this input:

   /OracleRules1_DecisionService_1" xmlns:ns2="http://xmlns.oracle.com/bpel">
         <resultList>
             <OrderApproval:OrderApproval      xmlns:OrderApproval="http://example.com/ns/customerorder"
   xmlns="http://example.com/ns/customerorder">
                 <status>approved</status>
             </OrderApproval:OrderApproval>
          </resultList>
     </callFunctionStatefulDecision>
   

In the SDK, there are shared Value Sets that can be associated with multiple conditions across Decision Tables. However, in Excel there are no shared Value Sets--each condition has its own Value Set--so you can only export a Value Set if it is modifiable in Excel. The Value Sets that are non-modifiable include:

• Linked Dictionary Value Sets.

• Enums.

• Internal Value Sets, for example, boolean Value Sets.

In the worksheet, you can only select values from the drop down for the conditions associated with non-modifiable Value Sets. A highlighting mechanism informs you which conditions are associated with non-modifiable Value Sets.

The export and import functionality is invoked using the toolbar button, as shown in Figure 5-45.

Figure 5-45 Export and Import Toolbar Button

Description of "Figure 5-45 Export and Import Toolbar Button"

1. In Rules Designer, click Export to Excel.
2. In the Export to Excel dialog box, select the Format and browse to the folder where you want to save the workbook.
3. Click Add and select the Decision Table(s) to export and click OK.
4. Check the Read Only Value Set check box to make all of the value sets read-only in Excel. There will not be any Value Sets sheet in the Excel workbook. All conditions will have drop down menus from which values can be selected but no values can be added or removed.
5. Click Export. You can now open the workbook and edit the Decision Table.

1. In Rules Designer, click Import from Excel.
2. In the Import from Excel dialog box, select the File to browse to the folder where you saved the workbook.
3. The Perform Diff-Merge on Import check box is selected by default. Browse to the Base Dictionary that you want to compare your file to. The base dictionary is required for a 3 way diff-merge.
4. Clear the Perform Diff-Merge on Import check box and select Create New or Overwrite.
5. Click Import. The decision table is imported into Rules Designer, where you can accept or reject changes, as shown in Figure 5-46. Each changed artifact is flagged with a change icon. Merging dictionaries should be done with caution.

   For more information about using the Diff-Merge, see How to Compare or Merge Two or More Dictionaries.

   Figure 5-46 Perform Diff-Merge on Import

   
   Description of "Figure 5-46 Perform Diff-Merge on Import"

In Excel, enable the macros to view the Oracle Business Rules tab, which provides you with options to author rules, edit Value Sets, and set preferences.