You do not have to assign Responsible User(s) to the Update Documents Action. The responsible Users are those who already have a role in the Document(s): (Author(s), Reviewer(s), Approver(s), QA(s).
If the Update Documents Action was added to the CAPA while it was in Created status then the Responsible Users will receive an email notification indicating that the Document(s) need to be updated when the CAPA reaches Implementing status.
If the Update Documents Action was added to the CAPA while it was in Implementing status, then the Responsible Users will receive an email notification indicating that the Document(s) need to be updated as soon as the Action is saved.
Relevant for: Administrators / Managers / Regular Users.