Case Nodes in Policy Designer

The Properties window for a Case node contains the items that are described in the following table.

Item	Description	Notes
Input section	Specifies the field whose value you want to compare to each If Input = value in order to determine the output(s) of the Case node.	If you select a comparison Condition node as a predecessor node, the logical result of the condition will be used automatically as the input value.
If Case section
If Input = text box	Specifies the value that must match the value that is defined in the Input section in order for the corresponding If Case to be executed.	You can use the and buttons in the If Input = row to add or delete If Cases in the Case node.
Output section	Specifies the output(s) for the corresponding If Case. The output section contains two columns: Mapping: Specifies a name for each output that you define. Value: Specifies the value or collection that will be the output of the Case node if the corresponding Case is executed.	You can use the and buttons in the output section to add or delete output rows. When you add or delete an output row in one Case, corresponding output rows in all cases are added or deleted automatically.
Else Case section
Else output section	Specifies the output(s) of the Else Case. The Else Case will be executed if the value in the If Input = section does not match any value defined in an If Input = text box.	This output section contains the same functionality as described above. You cannot delete the Else Case from the Case node.

You can use the Case node in the policy model to change a node's output values so that they can be used in successor nodes to perform calculations or actions. For example, you can use the Case node to convert character-based values from a Health Indicator reading or an AMS Asset status message to numeric values that you can use in subsequent calculations.

Consider the following policy model in which reading values from a character-based Health Indicator record are converted to numeric values. The values are then added to a Health Indicator record that uses numeric values.

As shown in the following image, you can use the Properties window of the Case node to indicate that the output value of the Case node will differ depending on the reading values associated with the Character Health Indicator node.

In this example, one output, HI Value, is defined. For this output, if the value in the Last Char Reading Value field is:

• 1-OK, the output value of the Case node will be 100. This is an If Case.
• 2-Not OK, the output value will be 50. This an another If Case.
• Any other value, the output value will be 0. This is the Else Case.

These values represent the numeric equivalents of the character-based readings associated with the Character Health Indicator node.

As shown in the following image of the Properties window of the Add Value to Health Indicator node, you can add the converted values to a numeric-based health indicator by selecting the HI Value output from the Case node.

You can use the Case node to combine policy logic in situations when a Condition node's successor nodes are the same in each logic branch. Rather than creating separate logic paths with duplicate nodes, you can use a Case node to define different outputs for each logical result of the condition. This is especially useful in large policy models with multiple logic branches and duplicate nodes.

The following image shows what a policy that uses Condition nodes looks like without Case nodes in the model.

Notice that the Add Value to Health Indicator node appears three times, and the Email Contact node appears twice.

The following image shows what the same policy looks like when you use Case nodes in the model.

In this model, each Case node takes the place of a logic branch. Rather than splitting the model into separate logic paths, the Case node supplies a specified output corresponding to the logical result of the preceding Condition node. Notice that in this model the Add Value to Health Indicator node and the Email Contact node appear only once.

The following image shows what the Properties window looks like for the first Case node in the preceding image.

In this example, if the logical result of the Condition node named Greater Than is:

• Yes, the output of the node will be 50.
• No, the output will be 0.

When Output 1 is selected as the input of a successor node, the GE Digital APM system will supply the corresponding value to the successor node.