 System operators are responsible for ensuring that power supply and loads remain balanced, and for keeping the system within safe operational limits such that no single fault can cause the system to fail.After a failure affecting their system, operators must obtain more power from generators or other regions or "shed load" (meaning to intentionally cut power or reduce voltage to a given area) until they can be sure that the worst remaining possible failure anywhere in the system will not cause a system collapse.In an emergency, they are expected to immediately shed load as required to bring the system into balance.