Only the Change Manager has the authority to approve the change. Any technician with the SD change manager role permissions can approve the change. A change manager can or could not be a member of the CAB. If needed the change manager can reject the change though the change is recommended by the CAB members. It is to the change manager's discretion whether to approve or reject the change.
Once the change is recommended by the CAB members the Change Manager should Approve or Reject the change. Except for the Standard Change type all other change type should be approved the change manager. The standard change type is a pre-approved change type hence it does not require any approval from the change manager. Only the approved changes will be taken further to solve the issue.
Approve the Change by the Change Manager
In the change details page Approval status of the change would show as Approved in a non-editable format. Also on the top right hand side of the page the Approval status of the change would change as Approved.