You can go further. There's a result that if you know how much processing time is left for a job, and can pre-empt it, then the most effective scheduling rule i

You can go further. There's a result that if you know how much processing time is left for a job, and can pre-empt it, then the most effective scheduling rule is "Shortest Remaining Processing Time" or SRPT. Harchol-Balter calls this the All-Can-Win Theorem, because it counterintuitively shows that jobs with more time to go being interrupted by jobs with less time to go will be better off. https://www.cs.cmu.edu/~harchol/all-can-win.pdf https://www.cs.cmu.edu/~harchol/all-can-win.pdf