The boarding process of an aircraft is one of the identified bottlenecks in the turnaround when aircraft arrives to an airport.

Simulation transparency is becoming more crucial in the decision making process when quantitative computer tools are used to justify some strategies.

Flexible production units provide very efficient mechanisms to adapt the type and production rate according to fluctuations in demand. The optimal sequence of the different manufacturing tasks in each machine is a challenging problem that can deal with important productivity benefits.