A technician can mark himself offline on his personalize icon.
A technician who logs out from the application or marks himself offline will be considered as offline technicians and requests will not auto-assigned to him on enabling this option "Assign only to online technicians".
This allows technicians to mark themselves offline to have them excluded from request auto-assignment when they are involved in critical tasks.
This is applicable for both Round Robin & Load Balancing model. When all technicians are offline, incoming requests will remain in the unassigned state.