The PCBU carrying out electrical work ensures it is not done on energised equipment (subject to r 157), that before work the equipment is tested by a competent person to determine whether it is energised, that every exposed part is treated as energised until isolated and proved de-energised, that high-voltage exposed parts are earthed after de-energising, and that de-energised equipment is not inadvertently re-energised while work continues (lockout and tagging).
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.