There should be an OOTB metric already configured. In your filter navigator, go to metric_definition.list. In the name field, search for "Assigned to duration" (this is on the incident table).
If you need to create your own, go back to the list, click New, and use the following settings:
- Name: enter a name of your choice
- Table: whatever table you want
- Field: Assigned to
- Type: Field value duration
- Active: true
- Timeline: (optional)
No scripting is required. You will see records populate on metric_instance.list when you change the Assigned to user on cases.
