Flight and Maintenance Planning of Military Aircraft for Maximum Fleet Availability: A Biobjective Model

model, military application Summary: Every aircraft, military or civilian, must be grounded for maintenance after it has completed a certain number of flight hours since its last maintenance check. Flight and maintenance planning of military aircraft addresses the problem of deciding which available aircraft to fly and for how long, and which grounded aircraft to perform maintenance operations on, in a set of aircraft that comprise a combat unit. The objective is to achieve maximum availability of the unit over the planning horizon. In this work, we develop a biobjective optimization model of the flight and maintenance planning problem, and we illustrate its application and solution on a real life instance drawn from the Hellenic Air Force. We formulate the flight and maintenance planning problem as a mixed integer linear program, with two objectives: total number of available aircraft and total residual flight time. The residual flight time of an available aircraft is defined as the total remaining time that this aircraft can fly, until it has to be grounded for maintenance check. For the solution of the problem we apply the weighted sums approach and lexicographic optimization. By comparing and analyzing the solutions obtained, we get insight into the behavior of the model. We conclude with a discussion based on these results and suggestions on how the model can be extended in the future