What is the use of 'refresh impacted services' ui action in the context menu in Incident application

[Suggy]

What is the use of 'refresh impacted services' ui action in the context menu in Incident application?

Once the CI is selected in the Configuration item field, upon saving the inc form, will the impacted services related list automatically populate or should we manually click on  'refresh impacted services' UI action?

If it gets populated automatically automatically upon saving the form, then why that UI action is given?

[Suggy]

@Runjay Patel Thanks for replying, I am aware of the process but I am looking for technical details of it. like which tables it refers etc .... also I added a CI on a new INC form, but upon submitting/saving the form, the Impacted services are not added automatically. I had to click on 'Refresh Impacted Services' UI action  to populate the same even though its a new INC.