In 2015, the FAA began looking to rationalize ILS approaches. In this context, rationalize means cut. The following year, the FAA developed a cost/benefit quantitative model and conducted an analysis at about 2900 airports with few or no RNAV SIDs or STARs. The finished product was a plan to decommission Cat I ILS approaches at some of these airports between 2020-2030. Before a decision was reached, the project was shelved in 2017.