Tail Assignment in Practice

Abstract

Tail Assignment is the problem of assigning specific aircraft to flights, producing a fully operational, robust schedule which fulfills operational constraints, while minimizing a cost function. The costs are usually related to robustness and quality of the solution, e.g. to penalize short times between flights and reward “crew-friendly” connections. Carmen Systems’ Tail Assignment system utilizes a combination of optimization methods and constraint programming to solve this problem. An interesting aspect of the system is that it can solve several fleet types at once, moving towards an integration of the traditional two-step approach of first solving the Fleet Assignment problem and then Tail Assignment. The article intends to explain some of the methods used.