In the first of a series of blogs we evaluate the benefits of bringing optimization to tail assignment: a complex process where small percentage gains can yield a significant financial return.
Airline scheduling is a complex process requiring countless variables (flight routes, crew, aircraft and airport restrictions, aircraft maintenance requirements…) to be defined and optimized in order to create the best possible schedule.
One critical component of airline scheduling is tail assignment optimization, which can help airlines unlock significant efficiency gains and cost reductions.
Tail Assignment is the problem of assigning each individual aircraft (identified by its tail number) to each flight in an optimal way. By optimizing tail assignments, airlines can fly their existing fleet in the most efficient way, by reducing fuel consumption (thus also lowering carbon emissions), improving aircraft utilization (fly more with the same number of aircrafts), and reducing navigation fees, landing fees, maintenance costs and more… Additionally, optimized tail assignments can help airlines, by creating a more robust schedule, to reduce (or even avoid) costly delays and cancellations.
The term “Tail Assignment” is used in two contexts:
Both contexts require similar optimizations, except that in the operational tail assignment there is more and better information available and the crew scheduling has already been executed, so much more info can (and should) be taken into account. This in contrast to “Planning Tail Assignment”, which is usually done before the crew scheduling.
Just like other types of scheduling, tail assignment is an optimization problem, which due to the high amount of degrees of freedom (factors or variables), results in an almost infinite number of possible suitable outcomes. Sophisticated mathematical models allow to efficiently converge towards an optimal solution.
The factors to be considered include aircraft availability, crew availability, airport restrictions, work regime constraints, operational costs, maintenance needs, fuel consumption, and more. By considering all of these factors and weighing them against each other, tail assignment optimization software can generate an optimized schedule that minimizes costs and maximizes efficiency.
To understand more clearly which gains tail assignment can bring, we should consider the typical cost structure (obviously this will vary a lot) of a sample airline:
This split-up shows that reducing fuel consumption, pilot or cabin crew labor costs or aircraft maintenance costs even by a few percentage can generate enormous cost savings and this is exactly what good tail assignment optimization software can deliver.
In our next blog we will dive into the cost model and constraints behind the tail assignment optimization.