A model and computational tool for crew scheduling in train transportation of mine materials by using a local search strategy

This work introduces a model of the crew scheduling problem for the operation of trains in the mining industry in the North of Chile. The model possesses particular features due to specific regulations with which train operators in mine material transportation are required to comply: every week, a fixed set of trips must be made according to current demand for the transportation of mine products and supplies. In order to balance the loads of the crews in the long term, the proposed model generates an infinite horizon schedule by means of a rotative scheme in which each crew takes the place of the previous one at the beginning of the next week. This gives rise to a medium/large size 0–1 linear optimization problem, whose solution represents the optimal assignment of drivers to trips with the number of working hours per week distributed equally among crews. The model and algorithm have been implemented with a user interface suitable for the remote execution of real instances on a High Performance Computing platform. The transportation company regularly uses this computerized tool for planning crew schedules and generating efficient assignments for emerging and changing operational conditions.