Process suspension
Many OS are built around (Ready, Running, Blocked) states. But there is one more state that may aid in the operation of an OS - suspended state.
When none of the processes occupying the main memory is in a Ready state, OS swaps one of the blocked processes out onto to the Suspend queue.
When a Suspended process is ready to run it moves into “Ready, Suspend” queue. Thus we have two more state: Blocked_Suspend, Ready_Suspend.