Shared responsibility often leads to misunderstandings. When the people involved rely on the others to manage that responsibility.

Even if the responsibility is assigned to a role, and that role is given to one person only, it’s often the case that the person hasn’t allocated time to actually perform the duties.

Every process, that’s required, needs to be assigned to a role and that role needs to be assigned to a person, who is actually expected to responsibly spend time on performing these duties.