A Decomposition Approach to Railway Crew Rostering Problems for Fair Labor Condition

The railway crew rostering problem aims to find an optimal assignment and cyclic sequence of crew duties to a set of rosters satisfying several labor conditions. We propose a novel decomposition approach to solve the railway crew rostering problem with the objective of fair labor condition in order to reduce the computational effort. The proposed method decomposes the original problem into two levels. The upper level master problem determines an assignment of crew duties to the set of rosters without sequencing, and the lower level subproblem generates a feasible cyclic sequence of crew duties including several resting times. Three types of effective cuts are proposed to reduce the feasible search space to tighten the gap between the solutions of the two level problems. Computational results demonstrate the effectiveness of the proposed method compared with that of the constrainted programming technique.