Sum (Average) of numeric values in linked issues
The Sum (Average) of numeric values in linked issues custom field allows you to define the value range for the number custom field type.
Create and configure the custom field
To create and configure the Sum (Average) of numeric values in linked issues custom field, you must be logged in as a user with Jira administrator permissions.
Go to Apps → Manage your apps → Custom Field Suite
Click on Create custom field button on the right side of the screen.
Select Sum (Average) and click Next.
Name and add a description to your field then click Next.
Define Sum or Average, Issue Type, and Numeric field you want to use.
Associate the field to the appropriate screens and click Create. You must associate a field to a screen before it will be displayed.
To restrict editing access for the Multilevel Select Picker, the Edit Permissions tab is used. Specific users, user groups, and Jira roles can be defined to have editing permissions for the custom field. If editing access is intended for all users, the field should be left empty.
Please note that the create screen has a separate toggle that allows defining whether users without edit permissions can create values in create screens.