This uses a series of queues which are given different priorities. They can be likeded to football league tables. (reference - OCR computing - Hodder education)

The premier league will get the first shot at the processor. Processes get added to this queue if they are I/O bound or short jobs.

When a process is running it will either -

• Block
• Give up control (voluntary)
• Be forced to stop (take too long)

If a process is forced to stop then it will be relagated to a lower queue. If a process blocks then it will automatically go to the top queue.

This algorithim is designed to change a processes priority as it runs based on what it is doing as well as how long it is taking.