Abstract
This paper addresses the scheduling of aircraft maintenance tasks that must be carried out in multiple maintenance checks to keep a fleet of aircraft airworthy. The allocation of maintenance tasks to maintenance opportunities, also known as the task allocation problem (TAP), is a complex combinatorial problem that needs to be solved daily by maintenance operators. We propose a novel approach capable of efficiently solving the multi-year task allocation problem for a fleet of aircraft in a few minutes. We formulate this problem as a time-constrained variable-sized bin packing problem (TC-VS-BPP), extending the well-known variable-sized bin packing problem (VS-BPP) by adding deadlines, intervals, and arrivals for the repetition of tasks. In particular, we divide the planning horizon into variable size bins to which multidimensional tasks are allocated, subject to available labor power and task deadlines. To solve this problem, we propose a constructive heuristic based on the worst-fit decreasing (WFD) algorithm for TC-VS-BPP. The heuristic is tested and validated using the maintenance data of 45 aircraft from a European airline. Compared with the solution obtained with an approach using an exact method, the proposed heuristic is more than 30% faster for all the test cases discussed with the airline. Most of the cases have optimality gaps below 3%. Even for the extreme case, the optimality gap is still smaller than 5%.
Highlights
Modern airliners have thousands of parts, systems, and components that need to be recurrently maintained after undergoing certain flight hours (FH), flight cycles (FC), calendar days (DY), or months (MO)
Despite the various task allocation models and methods discussed before, the task allocation problem (TAP) of aircraft maintenance is very analogous with bin packing problem (BPP), where for TAP, the maintenance opportunities are equivalent to bins, and maintenance tasks are considered as items
The proposed heuristic is more than 30% faster than the exact method for the default productivity factor of 4.8 labor hours, and the optimality gap is only 0.03%
Summary
Modern airliners have thousands of parts, systems, and components that need to be recurrently maintained after undergoing certain flight hours (FH), flight cycles (FC), calendar days (DY), or months (MO). It means that they either have to be allocated to a more frequent letter check or manually allocated by maintenance operators to different maintenance events based on the suitability of the task to that check and the urgency of performing the task in due time Both approaches are conducted according to the experience of maintenance planners, leading to inefficiencies. Inspired by the bin packing problem (BPP), we consider pre-scheduled maintenance checks to be bins of different (time) dimensions and sharing a multi-dimensional capacity, referring to the multiple types of labor skills involved in the execution of the tasks. This work is the first to formulate the TAP as a bin packing problem and solve it with an efficient constructive algorithm. The last section summarizes the research with concluding remarks and gives an outlook on future work
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
