Mining Goes Digital – Mueller et al. (Eds)
© 2019 Taylor & Francis Group, London, ISBN 978-0-367-33604-2
419
Optimization model for rostering and crew assignment for
train transportation
J. Amaya & E. Molina
Department of Mathematical Engineering and Center for Mathematical Modeling, University of Chile,
Santiago, Chile
N. Morales
Delphos Lab., Advanced Mining Technology Center, University of Chile, Santiago, Chile
P. Uribe
Center for Mathematical Modeling, University of Chile, Santiago, Chile
ABSTRACT: This work introduces a model and software for the rostering and crew scheduling problems, for train operation in the mining industry in Chile. The transportation rail
network covers most of locations of the industry in the North of the country, including
mines, plants and ports. The model possesses particular features due to specific regulations
with which train operators in mine material transportation are required to comply. 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 changing operational conditions. The problem has been partitioned in two
steps. Firstly, through a linear mixed integer optimization model, every trip is divided in elemental segments to be served by the crews. Secondly, another optimization model produces
the crew assignment to fulfil all the trips demand. The optimization instances are solved
by using Gurobi, coded in AMPL and it permits an efficient management of the human
resources (drivers), equilibrating the workloads between them.
1 INTRODUCTION
This work introduces two mathematical models that are used together for the rostering
and crew scheduling problem, for the operation of trains in the mining industry in a large
geographic area located in Chile. The transportation rail network covers most of locations
of the industry in the very North of the country, including mines, plants and ports and
others.
The problem we are interested on has to deal with two main aspects. Firstly, train trips
can be very long, meaning that the same train may have different crew operating it over a the
train travel. Therefore, train-stops must be defined at which crew members can be replaced.
The location of these stops is limited by several reasons, like nearby location of urban towns,
and also they cannot be too far away from each other: in order to allow the crew replacement,
a maximum of 10.5 hours limitation, nor they can be too close to each other because that
would produce delays and make the transportation company unable to comply with demand.
Secondly, the transportation company needs to deal with all the logistics related to the crews:
at each train stop, a fresh crew takes over the train, so this crew had to be transported from a
base or camp; and conversely, another crew leaves for resting and needs to be taken back to
base. These crew transportation (from base to train and otherwise) are done using company
cars.
© 2019 Taylor & Francis Group, London, ISBN 978-0-367-33604-2
419
Optimization model for rostering and crew assignment for
train transportation
J. Amaya & E. Molina
Department of Mathematical Engineering and Center for Mathematical Modeling, University of Chile,
Santiago, Chile
N. Morales
Delphos Lab., Advanced Mining Technology Center, University of Chile, Santiago, Chile
P. Uribe
Center for Mathematical Modeling, University of Chile, Santiago, Chile
ABSTRACT: This work introduces a model and software for the rostering and crew scheduling problems, for train operation in the mining industry in Chile. The transportation rail
network covers most of locations of the industry in the North of the country, including
mines, plants and ports. The model possesses particular features due to specific regulations
with which train operators in mine material transportation are required to comply. 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 changing operational conditions. The problem has been partitioned in two
steps. Firstly, through a linear mixed integer optimization model, every trip is divided in elemental segments to be served by the crews. Secondly, another optimization model produces
the crew assignment to fulfil all the trips demand. The optimization instances are solved
by using Gurobi, coded in AMPL and it permits an efficient management of the human
resources (drivers), equilibrating the workloads between them.
1 INTRODUCTION
This work introduces two mathematical models that are used together for the rostering
and crew scheduling problem, for the operation of trains in the mining industry in a large
geographic area located in Chile. The transportation rail network covers most of locations
of the industry in the very North of the country, including mines, plants and ports and
others.
The problem we are interested on has to deal with two main aspects. Firstly, train trips
can be very long, meaning that the same train may have different crew operating it over a the
train travel. Therefore, train-stops must be defined at which crew members can be replaced.
The location of these stops is limited by several reasons, like nearby location of urban towns,
and also they cannot be too far away from each other: in order to allow the crew replacement,
a maximum of 10.5 hours limitation, nor they can be too close to each other because that
would produce delays and make the transportation company unable to comply with demand.
Secondly, the transportation company needs to deal with all the logistics related to the crews:
at each train stop, a fresh crew takes over the train, so this crew had to be transported from a
base or camp; and conversely, another crew leaves for resting and needs to be taken back to
base. These crew transportation (from base to train and otherwise) are done using company
cars.