Access Management is closely related to which other processes?

Availability Management alone is insufficient because Access Management also requires Information Security Management to establish the policies that determine who is authorized to receive access.

3rd line support is an operational support tier, not a formal ITIL process that Access Management is defined as being closely related to; Availability Management is the correct second process.

Access Management depends on Information Security Management to define the policies, standards, and security controls that govern who is permitted access to which services and data. It also interfaces with Availability Management because both processes share responsibility for ensuring that legitimate users can reach services when needed - Access Management controls the grant of rights while Availability Management ensures the service is operational and reachable.

Limiting the relationship to Information Security Management alone omits Availability Management, which is a key partner process ensuring that services are accessible to the users who have been granted rights.