Renaming an interface operation can break your application if you do not also update all the dependencies that use the former operation name. Refactoring makes those updates for you automatically after you preview and accept the changes.
Although you can edit the operations of an interface directly in the editor, in most cases you should use refactoring. If you rename an operation by editing the object in the editor, the operation will have a new name, but no relationships that use the former name will change.
To change the name of an operation and all the dependencies that use the name: