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1.
When tracks are out of service for maintenance during a certain period, trains cannot be operated on those tracks. This leads to a modified timetable, and results in infeasible rolling stock and crew schedules. Therefore, these schedules need to be repaired. The topic of this paper is the re-scheduling of crew. 相似文献
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Matias Sevel Rasmussen Tor Justesen Anders Dohn Jesper Larsen 《European Journal of Operational Research》2012
In the Home Care Crew Scheduling Problem a staff of home carers has to be assigned a number of visits to patients’ homes, such that the overall service level is maximised. The problem is a generalisation of the vehicle routing problem with time windows. Required travel time between visits and time windows of the visits must be respected. The challenge when assigning visits to home carers lies in the existence of soft preference constraints and in temporal dependencies between the start times of visits. 相似文献
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The railway crew scheduling problem consists of generating crew duties to operate trains at minimal cost, while meeting all work regulations and operational requirements. Typically, a railway operation uses tens of thousands of train movements (trips) and requires thousands of crew members to be assigned to these trips. Despite the large size of the problem, crew schedules need to be generated in short time, because large parts of the train schedule are not finalized until few days before operation. 相似文献
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Vehicle and crew scheduling for urban bus lines 总被引:1,自引:0,他引:1
Maikol M. Rodrigues Cid C. de Souza Arnaldo V. Moura 《European Journal of Operational Research》2006,170(3):844-862
A solution to the urban transportation problem is given by vehicle and crew schedules. These schedules must meet the passenger demand and satisfy technical and contractual restrictions stemming from the daily operation of the lines, while optimizing some measure of operational cost. This work describes a computational tool developed to solve the urban transportation problem in the large metropolitan area of São Paulo, Brazil. The techniques used are based on integer programming models coupled with heuristics. The former produces good feasible solutions, and the latter improves the quality of the final solutions. While the operational and labor restrictions are specific to the city of São Paulo, the same ideas can inspire similar approaches for solving the urban transportation problem arising in other metropolitan areas. 相似文献
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This paper presents a computationally effective heuristic method which produces good-quality solutions for large-scale set
covering problems with thousands of constraints and about one million variables. The need to solve such large-scale problems
arises from a crew scheduling problem of mass transit agencies where the number of work shifts required has to be minimized.
This problem may be formulated as a large-scale non-unicost set covering problem whose rows are trips to be performed while
columns stand for round trips. The proposed method is mainly based on lagragian relaxation and sub-gradient optimization.
After the reduction of the number of rows and columns by the logical tests, “greedy” heuristic algorithms provide upper and
lower bounds which are continuously improved to produce goodquality solutions. Computational results, regarding randomly generated
problems and real life problems concerning crew scheduling at Italian Railways Company, show that good-quality solutions can
be obtained at an acceptable computational cost.
This work was supported by the project “Progetto Finalizzato Transporti 2” of National Research Council of Italy (C.N.R.)
contract No. 94.01436PF74 and by “Ferrovie dello Stato S.p.A.” 相似文献
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Alberto Caprara Matteo Fischetti Paolo Toth Daniele Vigo Pier Luigi Guida 《Mathematical Programming》1997,79(1-3):125-141
Crew management is concerned with building the work schedules of crews needed to cover a planned timetable. This is a well-known
problem in Operations Research and has been historically associated with airlines and mass-transit companies. More recently,
railway applications have also come on the scene, especially in Europe. In practice, the overall crew management problem is
decomposed into two subproblems, called crew scheduling and crew rostering. In this paper, we give an outline of different
ways of modeling the two subproblems and possible solution methods. Two main solution approaches are illustrated for real-world
applications. In particular we discuss in some detail the solution techniques currently adopted at the Italian railway company,
Ferrovie dello Stato SpA, for solving crew scheduling and rostering problems. 相似文献
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A typical railway crew scheduling problem consists of two phases: a crew pairing problem to determine a set of crew duties and a crew rostering problem. The crew rostering problem aims to find a set of rosters that forms workforce assignment of crew duties and rest periods satisfying several working regulations. In this paper, we present a two-level decomposition approach to solve railway crew rostering problem with the objective of fair working condition. To reduce computational efforts, the original problem is decomposed into the upper-level master problem and the lower-level subproblem. The subproblem can be further decomposed into several subproblems for each roster. These problems are iteratively solved by incorporating cuts into the master problem. We show that the relaxed problem of the master problem can be formulated as a uniform parallel machine scheduling problem to minimize makespan, which is NP-hard. An efficient branch-and-bound algorithm is applied to solve the master problem. Effective valid cuts are developed to reduce feasible search space to tighten the duality gap. Using data provided by the railway company, we demonstrate the effectiveness of the proposed method compared with that of constraint programming techniques for large-scale problems through computational experiments. 相似文献
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Mohammed Saddoune Guy Desaulniers Issmail Elhallaoui François Soumis 《European Journal of Operational Research》2011,212(3):445-454
The integrated crew scheduling (ICS) problem consists of determining, for a set of available crew members, least-cost schedules that cover all flights and respect various safety and collective agreement rules. A schedule is a sequence of pairings interspersed by rest periods that may contain days off. A pairing is a sequence of flights, connections, and rests starting and ending at the same crew base. Given its high complexity, the ICS problem has been traditionally tackled using a sequential two-stage approach, where a crew pairing problem is solved in the first stage and a crew assignment problem in the second stage. Recently, Saddoune et al. (2010b) developed a model and a column generation/dynamic constraint aggregation method for solving the ICS problem in one stage. Their computational results showed that the integrated approach can yield significant savings in total cost and number of schedules, but requires much higher computational times than the sequential approach. In this paper, we enhance this method to obtain lower computational times. In fact, we develop a bi-dynamic constraint aggregation method that exploits a neighborhood structure when generating columns (schedules) in the column generation method. On a set of seven instances derived from real-world flight schedules, this method allows to reduce the computational times by an average factor of 2.3, while improving the quality of the computed solutions. 相似文献
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Yufeng Yao Özlem Ergun Ellis Johnson William Schultz J.M. Singleton 《European Journal of Operational Research》2008
In the fractional ownership model, the partial owner of an aircraft is entitled to certain flight hours per year, and the management company is responsible for all the operational considerations of the aircraft and for making an aircraft available to the owner at the requested time and place. In the recent years although the industry as a whole has experienced significant growth, most of the major fractional jet management companies have been unprofitable. To increase profitability a management company must minimize its operating costs and increase its crew and aircraft utilization. In this paper, we present a methodology for efficiently scheduling the available resources of a fractional jet management company that takes into consideration the details in real world situations. We then discuss several strategic planning issues, including aircraft maintenance, crew swapping, demand increase and differentiation, and analyze their effects on the resource utilization and profitability. 相似文献