It's only 15 minutes, but in the world of commercial aviation, on-time performance is a crucial measure for every airline.
Interestingly, few airlines strive to be 100 percent on time. In fact, reaching 100 percent OTP is all but impossible, and if achieved, it would have a negative effect on profits and financial performance. External factors ranging from weather, poorly located airport gates, industrial disputes or long immigration queues all can result in delays. While many airlines have sophisticated operational programs and technology to juggle and optimize schedules on a daily basis, the marginal costs associated with 100 percent punctuality are crippling. Imagine the impact of having six or seven aircraft and crew on permanent standby for those "just in case" moments where OTP can be marginally improved. Shareholders would balk at such a suggestion.
That doesn't mean punctuality isn't important. An airline that consistently operates late is simply unacceptable. For time-sensitive business travelers, planning a busy schedule with an arriving airline that consistently operates late can ruin an entire day of meetings. For a passenger connecting to another flight—typically, over 30% of travelers do every single day—delays can be crippling.
Measuring on-time performance clearly is an important metric for airlines. But is 15 minutes the right measurement?
The 15-minute principle is applied to all flights regardless of sector length. For example, a Los Angeles-San Francisco flight with a one hour, 31-minute schedule is treated the same as a New York-Singapore flight that's 18 hours and 30 minutes. Is that reasonable? Would it make more sense to allow a greater degree of latitude for longer flights, with some form of proportional measurement related to distance flown? While that may sound reasonable on paper, it's not the best idea.
The levels of planning and data gathered around flight operations by industry aggregators equip carriers and airports to accurately plan sector times based on historic and seasonal performances around the globe. The database tracks sector lengths by flight times, days of the week, months and seasons, allowing airlines to track and plan with incredibly high levels of accuracy throughout the year. That degree of accuracy has allowed airlines to build sophisticated hub networks connecting ultra-long-haul sectors with short-haul feeder networks with increasing accuracy.
Airlines plan with 15-minute criteria and typically aim to achieve around 85 percent to-90 percent OTP throughout the year. Planning for a shorter time period of 10 minutes and striving to achieve a higher OTP level of 95 percent would require additional resources and lead to higher airfares for some travelers. A requirement for additional resources in terms of aircraft, crew and supporting operations wouldn't make sense.
Ultimately, on-time performance remains one of the few “hard” measurements we use to compare airlines against each other. Service levels are subjective, schedules and frequency are not important for all travelers and differ by location, and even low-cost airlines can have very high fares. Fifteen minutes may seem arbitrary, but it's the right metric for all involved: airlines, airports, and most importantly the customer.