[ESRI software] In ArcGIS Network Analyst, a type of network analysis for finding the closest locations (facilities) from sites (incidents), based on the impedance chosenfor example, finding hospitals near a car accident. When finding closest facilities, users can specify how many to find and whether the direction of travel is toward or away from the site (incident). Users can also specify a cutoff threshold beyond which ArcGIS Network Analyst will not search for a facilityfor example, finding hospitals within 6 miles of a car accident.