Improving Workforce Scheduling of Aircraft Line Maintenance at Sabena Technics

Abstract

This paper presents our application of a visualization tool and optimization model based on mixed-integer linear programming to solve a workforce staffing and scheduling problem at Sabena Technics, a major aircraft maintenance company in Belgium. We used the software to generate many alternative, cost-efficient schedules and to analyze multiple scenarios. In several management meetings, stakeholders evaluated the schedules and raised concerns. We subsequently changed the model to successfully address their concerns. The model has resulted in considerable savings and a more efficient use of human resources.

A three-stage approach for aircraft line maintenance personnel rostering using MIP, discrete event simulation and DEA

“…As mentioned in the introduction, we use the rosters built up by Beliën et al (2012). The objective of the MILP-model is to minimize the labor costs while satisfying a number of constraints, such as coverage constraints.…”

“…The solution algorithm of Beliën et al (2012) follows an enumerative approach and solves a MILP for each combination of team sizes for the different cycles. In order to avoid spending MILP time on combinations which cannot result in a better solution, each MILP is provided with a current upper bound (i.e., current best solution).…”

“…One constraint in the MILP-approach of Beliën et al (2012) is the implementation of a time buffer after the flight arrival. This buffer avoids problems in the event of a flight delay.…”

“…Real-time flight arrival data for the winter season in 2008 are used in order to identify the appropriate delay distributions. These distributions are applied to the list of flights that was also the input for the MILP-approach (Beliën, et al, 2012). In the simulation, decisions are made every 15 minutes and the planning horizon is divided into quarters of an hour (i.e., each period equals 15 minutes).…”

“…These rosters are the results of the mixed integer linear programming (MILP) model of Beliën, Demeulemeester and Cardoen (2012). In their model, they try to protect the maintenance schedule from flight arrival delays by scheduling no maintenance jobs during a certain time period after the scheduled time of arrival (STA).…”