J1, … J2, J3, … J1, J2, … J1, J3, … Illustrative Example: Bounding Operation #2 All possible schedules for 4 jobs J2, … J1, … J4, … J3, … 540 490 550 510 J2, J4, … 560 570 560 J4, J3, … 620 540 550 J1, J4, … 570 640 540 J1, J4, J2, J3 J1, J4, J3, J2 550 540 Upper bound (UB) of the minimum makespan If we know for sure that no schedule with a shorter makespan will be found in a node, we need not investigate the node further.