 The aim is to eliminate or reduce all risks to a low level.  For each significant hazard, determine whether the remaining risk, after all precautions have been taken, is high, medium or low.  Concentrate on the greatest risks first.  Examine how work is actually carried out and identify failures to follow procedures or practices.  Need to comply with legal requirements and standards.  The law says that you must do what is reasonably practical to keep your workplace safe.