As MidLifeXis and BrowserUK imply, the requirement "ANY PROCESS AT ANY TIME SHOULD NOT USE MORE THAN 70% OF CPU" seems to be incorrectly specified. Rarely do you care what percentage of the CPU is spent on any particular process. Usually you care that the system is always responsive to the console, or that processes aren't CPU or I/O starved or some other criterion. Thus, the original statement appears to be symptom-related rather than requirement-related. You might ask them to restate the requirement in a more meaningful form. Otherwise, you'll have to do ridiculous things like consuming a third of the CPU in a high-priority process or otherwise discarding CPU cycles when they're otherwise unneeded by other processes.