Delta's Operational Performance Commitment has changed how it measures on-time performance.
Previously, a flight was categorized as on time if it arrived at the gate within 15 minutes of its scheduled time. Now, a flight must arrive at the gate by the exact scheduled time to be considered to be on time.
The change puts Delta's commitment -- which offers eligible corporate clients compensation should its performance metrics fall below those of both American Airlines and United Airlines --in line with the way United measures on-time performance.
Delta's 2016 on-time performance beat American's and United's by either measure, according to the carrier, which reported that its commitment covers more than 2,000 corporate accounts.
Source: Business Travel News