Who is responsible for ensuring that the request fulfillment process is being performed according to the agreed and documented standard?

The IT director has overall strategic and organizational responsibility but is not accountable for the execution of individual processes.

In ITIL, the process owner is responsible for the governance of a specific process, including ensuring it is performed as documented and meets agreed standards. This role holds accountability for process quality, compliance, and improvement - distinct from managing a service or directing the broader IT organization.

The service owner is accountable for a specific service across its lifecycle, not for governing how a process is performed.

The customer receives the outcomes of services and may define requirements, but is not responsible for internal process compliance.