Final answer:
The accounts manager should initiate a user account deprovisioning process to revoke a user's access rights and secure the system following an employee's departure.
Step-by-step explanation:
When a user no longer requires access to a given resource, or the user no longer works within the organization, the accounts manager should initiate the process of user account deprovisioning. This process involves revoking all access rights and permissions associated with the user's account in order to prevent unauthorized access.
The deprovisioning process should be thorough and can include disabling or deleting the user's account, changing passwords for shared accounts, and removing access to all systems, applications, and data to which the user had access. Additionally, any security credentials such as keys or tokens issued to the user should be invalidated. It is important to follow an established deprovisioning protocol to ensure the security of the system and to protect sensitive information.