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Building the perfect schedule: what do airline schedulers really think about?


Finding that perfect combination of flights.   Serving many stakeholders in one planning problem.

That flight would be perfect if it was an hour earlier… or later… or on Tuesday.   From the outside many of us have looked at airline schedules and thought how it could be better timed to suit our needs.  We look at it from a selfish perspective of course, and (most of us) get that it’s a complicated process, and that airlines are not building schedules just around one individual.  But have we ever thought about what might be going through the minds of the schedule builders themselves?

Commercial considerations?

When looking at a schedule the commercial teams will be focussed a lot on passengers; or probably more specifically the opportunity those passengers bring.  Every airline knows their customers.  But schedule builders like to know where, and when, do these customers want to fly?  Some schedule features will be universally popular or unpopular: no-one wants to get a flight at midnight.  Although maybe they do if it’s a long haul flight they can then sleep overnight and arrive at a good time at their destination, or maybe if the price is very cheap they will fly anytime!  Generally though, flights will appeal to different audiences: weekday early morning flights for business customers, weekend city break customers may like to fly back Sunday evening and so on.  I remember that one airline told us they used to time some flights around the potential honeymoon market.

Commercial teams also like to think of another dimension though: transfer passengers.  Not a group that is necessarily  relevant for all airlines but critical for network carriers.   Transfer passengers can be a significant proportion of a passenger flow on some flights; the ability to sell a well connected, and well priced, transfer can take customers away from other competitors offering a direct route.   Transfer markets are very schedule dependent though.   There is an obvious sweet spot for transfer connections: not too long to be unattractive, yet not too short to be rushed or risky if there are delays.

or operational priorities?

This seems like a good way of thinking about a schedule.  In crude terms how many passengers will it attract and can good prices be offered to these passengers.?  Surely the commercial teams have solved the problem?  Herein lies the actual issue.  There is an operations and planning team with a different perspective, different set of KPIs, a different thought process even. Day in and day out they are thinking of cost, punctuality, customer experience and asset utilization.

From an operational perspective there are a whole bunch of other considerations.  Firstly the schedule could be restricted by outside forces: airport curfews, slot restrictions, movement restrictions.  Even if these are not inhibiting, the planner needs to consider his or her own resources: stands, employees, airport vehicles.  Ideally from an operations perspective the schedule is uniform throughout the day.  The planner will also need to think about their aircraft; do they have an opportunity to visit a maintenance base regularly, can each aircraft fly to every airfield,  is the schedule generating too much cost in terms of pilots and cabin crew (for example through nightstops which might be incurred for at certain times of day based on sector lengths).

How to bring together a complex problem?

It now sounds like a really complex process, but yet it’s one every airline faces.  In reality they consider all elements: a multifaceted balancing act is juggled by schedule planners and network teams (and in reality the operational teams are not blind to commercial opportunities and vice versa).   The strength of this balancing act often relies on the strength of the processes, and communication lines between key stakeholders.  Organizational design can of course help and  even sometimes physical geography (if everyone sits next to each other things can be easier).  But ultimately the relationships are important.

Of course technology, and more specifically optimization, can also help this process.  Schedule building has so many different parts only sophisticated optimization techniques can evaluate these trade off all at once; and also, more importantly allow a number of scenarios to be evaluated.  Schedule building will always be an art and a science, it will have a subjective element to it, nevertheless optimization will allow more and more scenarios to be evaluated.  It will allow deeper searches and creates combinations that hadn’t previously been thought of.  It can help challenge operational and commercial teams alike in trading off the different components of a schedule.

So next time we are looking for a flight and can’t find the perfect fit, maybe we should consider how the airline generated that schedule.  Did operational or commercial considerations take precedence; or did the airline use a powerful and sophisticated optimizer to help?


Photo by Mourizal Zativa on Unsplash