The purpose of establishing engineered nurse staffing requirements in any area of nursing, including the emergency department (ED), is to ensure that the right resources (nurses) are in the right place (various locations throughout the emergency department) at the right times (covering all 24 hours of operation, 7 days a week). Implied in the foregoing statement is the right skill mix (right resources) of registered nurses, emergency medical technicians, unit secretaries, transporters, and the like.