for example, if four users (a,b,c,d) are concurrently executing one process each, the scheduler will logically divide the available cpu cycles such that each user gets 25% of the whole (100% / 4 = 25%). if user b starts a second process, each user will still receive 25% of the total cycles, but each of user b's processes will now be attributed 12.5% of the total cpu cycles each, totalling user b's fair share of 25%. on the other hand, if a new user starts a process on the system, the scheduler will reapportion the available cpu cycles such that each user gets 20% of the whole (100% / 5 = 20%).