Development of a decision support tool for capacity optimization of an aviation workshop

Abstract: Aircrafts needs to be maintained for many different reasons. To have a high safety and reduced costs, are two reasons. Both corrective and preventive maintenance are carried out on aircrafts. The preventive maintenance cost a lot of money and during the maintenance, the aircraft is not available for flying. In the Swedish Air Force the main aircraft flown is JAS 39 Gripen and it is a multirole aircraft.One major part of the preventive maintenance for the JAS 39 Gripen aircraft is to undertake overhauls. The overhauls are flight time dependent and needs to be carried out before the aircraft are allowed to fly again. During the overhaul, there are often a lot of other maintenance tasks carried out like repairs and modifications.A good plan for the required maintenance capacity in the workshops is essential to reduce the total maintenance cost. There is also another reason to have the right maintenance capacity and that is the availability of the fleet needs to be high enough. If the workshop capacity is too low, it will lead to a low availability of the aircrafts and that can lead to problems of achieving the targeted flight time production. One part in determining the workshops totally needed maintenance capacity is to determine the needed overhaul capacity. An optimization model has been developed during the thesis work as a decision support tool to determine the future need of the overhaul capacity. The model has been formulated as a cost minimization model of overhauls including queue cost and workshop capacity cost. To be able to construct the model the maintenance work at the Swedish Air Force has been studied.The parameters that is needed for the model have been described how they are defined and how to calculate them.Two cases are presented in the report and the needed parameter values used for the cases have been calculated to represent the year 2014. Under that year the first generation Gripen aircrafts are planned to been taken out of service and only the second generation ones are used. Verification of the model has been carried out and the model description is included in the report. To construct this model the overhaul work and the affecting factors have been studied.The developed model can be used as a support tool for decision makers in the Swedish Air Force to aid them to the right decisions.Suggestions of future work related to the area in the repot are given so the optimization of the maintenance can be improved even more.