---
sourceDocument: Brazil Telecommunications, Media, and Technology
sourceDocumentLink: https://www.servicenow.com/docs/r/telecom-media-technology

 Release :

    - brazil

ft:locale :

    - en-US

ft:publication_title :

    - Brazil Telecommunications, Media, and Technology

ft:clusterId :

    - telmt

bundleId :

    - telmt

workflow :

    - Customer and Industry


---

# Define a decomposition rule

# Define a test decomposition rule {#ariaid-title1}

Release version: Brazil  
Updated October 26, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read  
Add a test decomposition rule to the mapping between a test group and a test definition to specify the characteristic and characteristic option that the rule uses.

## Before you begin

The Product Model plugin (com.sn_prd_pm) must be active. See [Plugins installed with Service Test Management](https://www.servicenow.com/docs/Qs8One~cB18gRXIUQRdk1w "Review the plugins that Service Test Management requires and the optional plugins that add characteristics, test decomposition, and conditional test groups.").

Define at least one characteristic for the test group. For ore information,
see [Define a characteristic for a test group](https://www.servicenow.com/docs/AYX~C0zWkjlm~_ql120AeA "Add a characteristic to a test group so that its test definitions can inherit the characteristic and the test group run can show it.").

Map the test definition to the test group. A test decomposition rule belongs to that mapping. For more information, see [Map test definitions to a test group](https://www.servicenow.com/docs/cgJW3dItjo_KevFWgLa6rg "Map test definitions to a draft test group and set the order in which they run.").

Role required: sn_st_mgmt.test_def_creator

## About this task

A test decomposition rule belongs to the mapping between a test group and a test definition, so you create it from that mapping.

## Procedure

1. Navigate to AllService Test ManagementTest GroupsAll.
2. Select the test group that you want to open.
3. In the Test Group To Definition Mapping related list, open the mapping for the test definition.
4. In the Test Decomposition Rules related list, select New.
5. On the form, fill in the fields.  
   {#define-test-decomposition-rule__table_dcr_03c_4de__entry__2}

   | Field | Description |
   |-|-|
   | Test Group Definition | Mapping between the test group and the test definition that the rule belongs to. |
   | Characteristic | Characteristic that the rule uses. The list shows only characteristics that belong to the test group. You must select a characteristic. |
   | Characteristic option | Option for the selected characteristic. The list shows only the options that you defined for that characteristic on the test group. |
   [Table 1. Test decomposition rule]

   {#define-test-decomposition-rule__table_dcr_03c_4de}
6. Select Submit.

## Result

The rule is added to the mapping. The system doesn't save a rule that has no test group definition or characteristic.

## What to do next

If the test group is in the Draft state, publish it when it is ready. See [Publish a test group](https://www.servicenow.com/docs/f~bNo9ck8VJZFMIWDcIhgA "Publish a test group so that you can relate it to a specification or a product model and your teams see only approved test groups.").

*[\>]: and then