Guy Desaulniers | École Polytechnique de Montréal (original) (raw)
Papers by Guy Desaulniers
Computers & Operations Research, 2015
In this article, we solve the pickup and delivery problem with time windows and last-in-first-out... more In this article, we solve the pickup and delivery problem with time windows and last-in-first-out (LIFO) loading. LIFO loading minimizes handling while unloading items from the vehicle: the items are loaded according to a linear stack structure, and an item can only be delivered if it is the one on top of the stack. Three exact branch-price-and-cut algorithms are available for this problem. These can solve instances with up to 75 requests within one hour. We propose a population-based metaheuristic capable of handling larger instances much faster. First, a set of initial solutions is generated with a greedy randomized adaptive search procedure. For each of these solutions, local search is applied in order to first decrease the total number of vehicles and then the total traveled distance. Two different strategies are used to create offspring. The first selects vehicle routes from the solution pool. The second selects two parents to create an offspring with a crossover operator. For both strategies, local search is then performed on the child solution. Finally, the offspring is added to the population and the best survivors are kept. The population is managed so as to maintain good quality solutions with respect to total cost and population diversity. Computational results on medium to large instances confirm the effectiveness of the proposed metaheuristic.
Computers & Operations Research, 2008
Dynamic constraint aggregation was recently introduced by Elhallaoui et al. [Dynamic aggregation ... more Dynamic constraint aggregation was recently introduced by Elhallaoui et al. [Dynamic aggregation of set partitioning constraints in column generation. Operations Research 2005; 53: 632–45] for efficiently solving the linear relaxation of a class of set partitioning type problems in a column generation context. It reduces the master problem size by aggregating some of its constraints and updates this aggregation when
Transportation Science, 2006
Abstract In this article we consider the problem of assigning parking slots to buses of different... more Abstract In this article we consider the problem of assigning parking slots to buses of different types so that the required buses can be dispatched easily in the morning. More precisely, if a bus of a certain type is needed at a given time, the buses that precede it in ...
International Journal of Computer Integrated Manufacturing, 2004
This paper presents an optimization methodology to design a network of manufacturing facilities p... more This paper presents an optimization methodology to design a network of manufacturing facilities producing several products, with non-trivial bills of material, under deterministic demands. The mathematical programming model developed finds the optimal structure of the manufacturing network, it defines the mission of the selected facilities and it determines the technology and the capacity of each facility. The approach takes economies
Transportation Science, 2000
The problem considered involves finding the minimum cost path, with cost and time being two indep... more The problem considered involves finding the minimum cost path, with cost and time being two independent quantities that govern the shortest path. In this problem, each arc is associated with a cost of traversing the arc as well as the time required to traverse it and each node is associated with a lower bound and an upper bound on the time of departure from that node. For example, the time at which a parcel can be sent from a FedEx dispatching station depends upon the working hours of the station. In this case the working hours on a particular day provide a lower and upper bound on the departure time at the node. The parcel dropped off at a station also has a certain waiting time before it
... Business Roar Grønhaug and Marielle Christiansen Section of Managerial Economics and Operatio... more ... Business Roar Grønhaug and Marielle Christiansen Section of Managerial Economics and Operations Research Norwegian University of Science and Technology Alfred Getz vei 3, N-7941 Trondheim, Norway e-mail: roar.gronhaug@iot.ntnu.no Abstract ...
International Journal of Robotic Research - IJRR, 1998
This paper addresses the problem of finding a shortest collision- free path for a carlike point r... more This paper addresses the problem of finding a shortest collision- free path for a carlike point robot maneuvering around polygonal obstacles in a room bounded by a polygonal line. The authors introduce a sufficient set of 56 subpath types for the no-obstacle case in which a subpath is defined as a piece of a path that starts and ends at either the initial position, the final position, or any position on a cell boundary. The authors propose a near-optimal algorithm that consists of finding a shortest path in a search graph where the arcs represent subpaths whose types belong to the sufficient set. The authors then study an algorithm in which the robot is allowed to turn on the spot at a certain cost. Finally, the authors compare the solutions derived from both algorithms.
European Journal of Operational Research - EJOR, 2007
Given buses of different types arriving at a depot during the evening, the bus parking problem co... more Given buses of different types arriving at a depot during the evening, the bus parking problem consists of assigning these buses to parking slots in such a way that they can be dispatched adequately to the next morning routes without moving them between their arrivals and departures. In practice, the bus arrival times deviate stochastically from the planned schedule. In this paper, we introduce for this problem two solution approaches that produce solutions which are robust to variations in the arrival times. The first approach considers that each arrival can deviate from its planned arrival order (sooner or later) by at most k positions, where k is a predefined parameter. In the second approach, the objective aims at minimizing the expectation of a function positively correlated with the number of buses that make the planned solution infeasible because they arrive too late or too early. In both approaches, the problem is modeled as an integer linear program that can be solved by a ...
Transportation Science, 2010
W e consider a maritime inventory routing problem in the liquefied natural gas (LNG) business, ca... more W e consider a maritime inventory routing problem in the liquefied natural gas (LNG) business, called the LNG inventory routing problem (LNG-IRP). Here, an actor is responsible for the routing of the fleet of special purpose ships, and the inventories both at the liquefaction plants and the regasification terminals. Compared to many other maritime inventory routing problems, the LNG-IRP includes some complicating aspects such as (1) a constant rate of the cargo evaporates each day and is used as fuel during transportation; (2) variable production and consumption of LNG, and (3) a variable number of tanks unloaded at the regasification terminals. The problem is solved by a branch-and-price method. In the column generation approach, the master problem handles the inventory management and the port capacity constraints, while the subproblems generate the ship route columns. Different accelerating strategies are implemented. The proposed method is tested on instances inspired from realworld problems faced by a major energy company.
Mathematical Programming, 2010
Dynamic constraint aggregation is an iterative method that was recently introduced to speed up th... more Dynamic constraint aggregation is an iterative method that was recently introduced to speed up the linear relaxation solution process of set partitioning type problems. This speed up is mostly due to the use, at each iteration, of an aggregated problem defined by aggregating disjoint subsets of constraints from the set partitioning model. This aggregation is updated when needed to ensure the exactness of the overall approach. In this paper, we propose a new version of this method, called the multi-phase dynamic constraint aggregation method, which essentially adds to the original method a partial pricing strategy that involves multiple phases. This strategy helps keeping the size of the aggregated problem as small as possible, yielding a faster average computation time per iteration and fewer iterations. We also establish theoretical results that provide some insights explaining the success of the proposed method. Tests on the linear relaxation of simultaneous bus and driver scheduling problems involving up to 2,000 set partitioning constraints show that the partial pricing strategy speeds up the original method by an average factor of 4.5.
In most vehicle routing and crew scheduling applications solved by column generation, the subprob... more In most vehicle routing and crew scheduling applications solved by column generation, the subproblem corresponds to a shortest path problem with resource constraints (SPPRC) or one of its variants. This chapter proposes a classification and a generic formulation for the SPPRCs, briefly discusses complex modeling issues involving resources, and presents the most commonly used SPPRC solution methods. First and foremost,
International Journal of Flexible Manufacturing Systems, 2000
This paper reports on the on-going development of a hybrid approach for dispatching and conflict-... more This paper reports on the on-going development of a hybrid approach for dispatching and conflict-free routing of automated guided vehicles used for material handling in manufacturing. The approach combines Constraint Programming for scheduling and Mixed Integer Programming for routing without conflict. The objective of this work is to provide a reliable method for solving instances with a large number of vehicles. The proposed approach can also be used heuristically to obtain very good solution quickly.
European Journal of …, 2006
Given the sets of flights and aircraft of an airline carrier, the fleet assignment problem consis... more Given the sets of flights and aircraft of an airline carrier, the fleet assignment problem consists of assigning the most profitable aircraft type to each flight. In this paper we propose a model for the periodic fleet assignment problem with time windows in which departure ...
Networks, 2009
A Branch-and-Price-Based Large Neighborhood Search Algorithm for the Vehicle Routing Problem with... more A Branch-and-Price-Based Large Neighborhood Search Algorithm for the Vehicle Routing Problem with Time Windows Eric Prescott-Gagnon and Guy Desaulniers École Polytechnique de Montréal and GERAD, CP 6079, Succursale Centre-Ville, Montréal, Québec, Canada ...
Transportation Science, 2008
The vehicle routing problem with time windows consists of delivering goods at minimum,cost to a s... more The vehicle routing problem with time windows consists of delivering goods at minimum,cost to a set of customers using an unlimited number of capacitated vehicles assigned to a single depot. Each customer must be visited within a prescribed time window. The most recent successful solution methods for this problem are branch-and- price-and-cut algorithms where the column generation subproblem is
Transportation …, 2001
... Simultaneous Vehicle and Crew Scheduling in Urban Mass Transit Systems. Knut Haase, Guy Desau... more ... Simultaneous Vehicle and Crew Scheduling in Urban Mass Transit Systems. Knut Haase, Guy Desaulniers, Jacques Desrosiers ... This paper presents an exact approach for solving the simultaneous vehicle and crew scheduling problem in urban mass transit systems. ...
International journal of …, 2004
This paper presents an optimization methodology to design a network of manufacturing facilities p... more This paper presents an optimization methodology to design a network of manufacturing facilities producing several products, with non-trivial bills of material, under deterministic demands. The mathematical programming model developed finds the optimal structure of the ...
The Dutch railway network experiences about three large disruptions per day on av- erage. In this... more The Dutch railway network experiences about three large disruptions per day on av- erage. In this paper, we present an algorithm to reschedule the crews when such a dis- ruption occurs. The algorithm is based on column generation techniques combined with Lagrangian heuristics. Since the number of duties is very large in practical instances, we rst dene a core problem
Journal of Scheduling, 2009
J Sched (2009) 12: 1730 DOI 10.1007/s10951-008-0072-x A comparison of five heuristics for the mu... more J Sched (2009) 12: 1730 DOI 10.1007/s10951-008-0072-x A comparison of five heuristics for the multiple depot vehicle scheduling problem Ann-Sophie Pepin · Guy Desaulniers · Alain Hertz · Dennis Huisman ... 1994; Desrosiers et al. 1995; Desaulniers and Hickman 2007). ...
Management …, 1997
In this paper we consider the daily aircraft routing and scheduling problem (DARSP). It consists ... more In this paper we consider the daily aircraft routing and scheduling problem (DARSP). It consists of determining daily schedules which maximize the anticipated profits derived from the aircraft of a heterogeneous fleet. This fleet must cover a set of operational flight legs ...
Computers & Operations Research, 2015
In this article, we solve the pickup and delivery problem with time windows and last-in-first-out... more In this article, we solve the pickup and delivery problem with time windows and last-in-first-out (LIFO) loading. LIFO loading minimizes handling while unloading items from the vehicle: the items are loaded according to a linear stack structure, and an item can only be delivered if it is the one on top of the stack. Three exact branch-price-and-cut algorithms are available for this problem. These can solve instances with up to 75 requests within one hour. We propose a population-based metaheuristic capable of handling larger instances much faster. First, a set of initial solutions is generated with a greedy randomized adaptive search procedure. For each of these solutions, local search is applied in order to first decrease the total number of vehicles and then the total traveled distance. Two different strategies are used to create offspring. The first selects vehicle routes from the solution pool. The second selects two parents to create an offspring with a crossover operator. For both strategies, local search is then performed on the child solution. Finally, the offspring is added to the population and the best survivors are kept. The population is managed so as to maintain good quality solutions with respect to total cost and population diversity. Computational results on medium to large instances confirm the effectiveness of the proposed metaheuristic.
Computers & Operations Research, 2008
Dynamic constraint aggregation was recently introduced by Elhallaoui et al. [Dynamic aggregation ... more Dynamic constraint aggregation was recently introduced by Elhallaoui et al. [Dynamic aggregation of set partitioning constraints in column generation. Operations Research 2005; 53: 632–45] for efficiently solving the linear relaxation of a class of set partitioning type problems in a column generation context. It reduces the master problem size by aggregating some of its constraints and updates this aggregation when
Transportation Science, 2006
Abstract In this article we consider the problem of assigning parking slots to buses of different... more Abstract In this article we consider the problem of assigning parking slots to buses of different types so that the required buses can be dispatched easily in the morning. More precisely, if a bus of a certain type is needed at a given time, the buses that precede it in ...
International Journal of Computer Integrated Manufacturing, 2004
This paper presents an optimization methodology to design a network of manufacturing facilities p... more This paper presents an optimization methodology to design a network of manufacturing facilities producing several products, with non-trivial bills of material, under deterministic demands. The mathematical programming model developed finds the optimal structure of the manufacturing network, it defines the mission of the selected facilities and it determines the technology and the capacity of each facility. The approach takes economies
Transportation Science, 2000
The problem considered involves finding the minimum cost path, with cost and time being two indep... more The problem considered involves finding the minimum cost path, with cost and time being two independent quantities that govern the shortest path. In this problem, each arc is associated with a cost of traversing the arc as well as the time required to traverse it and each node is associated with a lower bound and an upper bound on the time of departure from that node. For example, the time at which a parcel can be sent from a FedEx dispatching station depends upon the working hours of the station. In this case the working hours on a particular day provide a lower and upper bound on the departure time at the node. The parcel dropped off at a station also has a certain waiting time before it
... Business Roar Grønhaug and Marielle Christiansen Section of Managerial Economics and Operatio... more ... Business Roar Grønhaug and Marielle Christiansen Section of Managerial Economics and Operations Research Norwegian University of Science and Technology Alfred Getz vei 3, N-7941 Trondheim, Norway e-mail: roar.gronhaug@iot.ntnu.no Abstract ...
International Journal of Robotic Research - IJRR, 1998
This paper addresses the problem of finding a shortest collision- free path for a carlike point r... more This paper addresses the problem of finding a shortest collision- free path for a carlike point robot maneuvering around polygonal obstacles in a room bounded by a polygonal line. The authors introduce a sufficient set of 56 subpath types for the no-obstacle case in which a subpath is defined as a piece of a path that starts and ends at either the initial position, the final position, or any position on a cell boundary. The authors propose a near-optimal algorithm that consists of finding a shortest path in a search graph where the arcs represent subpaths whose types belong to the sufficient set. The authors then study an algorithm in which the robot is allowed to turn on the spot at a certain cost. Finally, the authors compare the solutions derived from both algorithms.
European Journal of Operational Research - EJOR, 2007
Given buses of different types arriving at a depot during the evening, the bus parking problem co... more Given buses of different types arriving at a depot during the evening, the bus parking problem consists of assigning these buses to parking slots in such a way that they can be dispatched adequately to the next morning routes without moving them between their arrivals and departures. In practice, the bus arrival times deviate stochastically from the planned schedule. In this paper, we introduce for this problem two solution approaches that produce solutions which are robust to variations in the arrival times. The first approach considers that each arrival can deviate from its planned arrival order (sooner or later) by at most k positions, where k is a predefined parameter. In the second approach, the objective aims at minimizing the expectation of a function positively correlated with the number of buses that make the planned solution infeasible because they arrive too late or too early. In both approaches, the problem is modeled as an integer linear program that can be solved by a ...
Transportation Science, 2010
W e consider a maritime inventory routing problem in the liquefied natural gas (LNG) business, ca... more W e consider a maritime inventory routing problem in the liquefied natural gas (LNG) business, called the LNG inventory routing problem (LNG-IRP). Here, an actor is responsible for the routing of the fleet of special purpose ships, and the inventories both at the liquefaction plants and the regasification terminals. Compared to many other maritime inventory routing problems, the LNG-IRP includes some complicating aspects such as (1) a constant rate of the cargo evaporates each day and is used as fuel during transportation; (2) variable production and consumption of LNG, and (3) a variable number of tanks unloaded at the regasification terminals. The problem is solved by a branch-and-price method. In the column generation approach, the master problem handles the inventory management and the port capacity constraints, while the subproblems generate the ship route columns. Different accelerating strategies are implemented. The proposed method is tested on instances inspired from realworld problems faced by a major energy company.
Mathematical Programming, 2010
Dynamic constraint aggregation is an iterative method that was recently introduced to speed up th... more Dynamic constraint aggregation is an iterative method that was recently introduced to speed up the linear relaxation solution process of set partitioning type problems. This speed up is mostly due to the use, at each iteration, of an aggregated problem defined by aggregating disjoint subsets of constraints from the set partitioning model. This aggregation is updated when needed to ensure the exactness of the overall approach. In this paper, we propose a new version of this method, called the multi-phase dynamic constraint aggregation method, which essentially adds to the original method a partial pricing strategy that involves multiple phases. This strategy helps keeping the size of the aggregated problem as small as possible, yielding a faster average computation time per iteration and fewer iterations. We also establish theoretical results that provide some insights explaining the success of the proposed method. Tests on the linear relaxation of simultaneous bus and driver scheduling problems involving up to 2,000 set partitioning constraints show that the partial pricing strategy speeds up the original method by an average factor of 4.5.
In most vehicle routing and crew scheduling applications solved by column generation, the subprob... more In most vehicle routing and crew scheduling applications solved by column generation, the subproblem corresponds to a shortest path problem with resource constraints (SPPRC) or one of its variants. This chapter proposes a classification and a generic formulation for the SPPRCs, briefly discusses complex modeling issues involving resources, and presents the most commonly used SPPRC solution methods. First and foremost,
International Journal of Flexible Manufacturing Systems, 2000
This paper reports on the on-going development of a hybrid approach for dispatching and conflict-... more This paper reports on the on-going development of a hybrid approach for dispatching and conflict-free routing of automated guided vehicles used for material handling in manufacturing. The approach combines Constraint Programming for scheduling and Mixed Integer Programming for routing without conflict. The objective of this work is to provide a reliable method for solving instances with a large number of vehicles. The proposed approach can also be used heuristically to obtain very good solution quickly.
European Journal of …, 2006
Given the sets of flights and aircraft of an airline carrier, the fleet assignment problem consis... more Given the sets of flights and aircraft of an airline carrier, the fleet assignment problem consists of assigning the most profitable aircraft type to each flight. In this paper we propose a model for the periodic fleet assignment problem with time windows in which departure ...
Networks, 2009
A Branch-and-Price-Based Large Neighborhood Search Algorithm for the Vehicle Routing Problem with... more A Branch-and-Price-Based Large Neighborhood Search Algorithm for the Vehicle Routing Problem with Time Windows Eric Prescott-Gagnon and Guy Desaulniers École Polytechnique de Montréal and GERAD, CP 6079, Succursale Centre-Ville, Montréal, Québec, Canada ...
Transportation Science, 2008
The vehicle routing problem with time windows consists of delivering goods at minimum,cost to a s... more The vehicle routing problem with time windows consists of delivering goods at minimum,cost to a set of customers using an unlimited number of capacitated vehicles assigned to a single depot. Each customer must be visited within a prescribed time window. The most recent successful solution methods for this problem are branch-and- price-and-cut algorithms where the column generation subproblem is
Transportation …, 2001
... Simultaneous Vehicle and Crew Scheduling in Urban Mass Transit Systems. Knut Haase, Guy Desau... more ... Simultaneous Vehicle and Crew Scheduling in Urban Mass Transit Systems. Knut Haase, Guy Desaulniers, Jacques Desrosiers ... This paper presents an exact approach for solving the simultaneous vehicle and crew scheduling problem in urban mass transit systems. ...
International journal of …, 2004
This paper presents an optimization methodology to design a network of manufacturing facilities p... more This paper presents an optimization methodology to design a network of manufacturing facilities producing several products, with non-trivial bills of material, under deterministic demands. The mathematical programming model developed finds the optimal structure of the ...
The Dutch railway network experiences about three large disruptions per day on av- erage. In this... more The Dutch railway network experiences about three large disruptions per day on av- erage. In this paper, we present an algorithm to reschedule the crews when such a dis- ruption occurs. The algorithm is based on column generation techniques combined with Lagrangian heuristics. Since the number of duties is very large in practical instances, we rst dene a core problem
Journal of Scheduling, 2009
J Sched (2009) 12: 1730 DOI 10.1007/s10951-008-0072-x A comparison of five heuristics for the mu... more J Sched (2009) 12: 1730 DOI 10.1007/s10951-008-0072-x A comparison of five heuristics for the multiple depot vehicle scheduling problem Ann-Sophie Pepin · Guy Desaulniers · Alain Hertz · Dennis Huisman ... 1994; Desrosiers et al. 1995; Desaulniers and Hickman 2007). ...
Management …, 1997
In this paper we consider the daily aircraft routing and scheduling problem (DARSP). It consists ... more In this paper we consider the daily aircraft routing and scheduling problem (DARSP). It consists of determining daily schedules which maximize the anticipated profits derived from the aircraft of a heterogeneous fleet. This fleet must cover a set of operational flight legs ...