The vehicle routing problem

This paper presents an overview of recovery models and algorithms for real-time railway disturbance and disruption management. This area is currently an active research area in Operations Research, including real-time timetable rescheduling and real-time rescheduling of the rolling stock and crew duties. These topics are addressed in this paper. Also research dealing with the integration of more than one rescheduling phase is discussed. Currently, the developed methods have been tested mainly in an experimental setting, thereby showing promising results, both in terms of their solution quality and in terms of their computation times. The application of these models and algorithms in real-life railway systems will be instrumental for increasing the quality of the provided railway services, leading to an increased utilization of the involved railway systems.

/pdf/an-overview-of-recovery-models-and-algorithms-for-real-time-121l19aesd.pdf

An overview of recovery models and algorithms for real-time railway rescheduling

A survey of recent research on location-routing problems

Ingredients of Locational Analysis (J. Krarup & P. Pruzan). The p-Median Problem and Generalizations (P. Mirchandani). The Uncapacitated Facility Location Problem (G. Cornuejols, et al.). Multiperiod Capacitated Location Models (S. Jacobsen). Decomposition Methods for Facility Location Problems (T. Magnanti & R. Wong). Covering Problems (A. Kolen & A. Tamir). p-Center Problems (G. Handler). Duality: Covering and Constraining p-Center Problems on Trees (B. Tansel, et al.). Locations with Spatial Interactions: The Quadratic Assignment Problem (R. Burkard). Locations with Spatial Interactions: Competitive Locations and Games (S. Hakimi). Equilibrium Analysis for Voting and Competitive Location Problems (P. Hansen, et al.). Location of Mobile Units in a Stochastic Environment (O. Berman, et al.). Index.

https://link.springer.com/content/pdf/10.1057%2Fjors.1991.208.pdf

Discrete location theory

This paper presents a survey of vehicle routing problems with multiple synchronization constraints. These problems exhibit, in addition to the usual task covering constraints, further synchronization requirements between the vehicles, concerning spatial, temporal, and load aspects. They constitute an emerging field in vehicle routing research and are becoming a “hot” topic. The contribution of the paper is threefold: (i) It presents a classification of different types of synchronization. (ii) It discusses the central issues related to the exact and heuristic solution of such problems. (iii) It comprehensively reviews pertinent literature with respect to applications as well as successful solution approaches, and it identifies promising algorithmic avenues.

Synchronization in Vehicle Routing---A Survey of VRPs with Multiple Synchronization Constraints

Solving a fuel delivery problem by heuristic and exact approaches

In this paper we consider the design problem of a two-echelon freight distribution system. The aim is to define the structure of a system optimizing the location and the number of two different kinds of facilities, the size of two different vehicle fleets and the related routes on each echelon. The problem has been modeled as a two-echelon location-routing problem (2E-LRP). A tabu-search heuristic efficiently combining the composing subproblems is presented. Results on small, medium and large size instances are reported.

A metaheuristic for a two echelon location-routing problem

An aggregation heuristic for large scale p-median problem

The Generalized Assignment Problem is a well-known NP-hard combinatorial optimization problem which consists of minimizing the assignment costs of a set of jobs to a set of machines satisfying capacity constraints Most of the existing algorithms are of a Branch-and-Price type, with lower bounds computed through Dantzig---Wolfe reformulation and column generation

In this paper we propose a cutting plane algorithm working in the space of the variables of the basic formulation, whose core is an exact separation procedure for the knapsack polytopes induced by the capacity constraints We show that an efficient implementation of the exact separation procedure allows to deal with large-scale instances and to solve to optimality several previously unsolved instances

/pdf/a-computational-study-of-exact-knapsack-separation-for-the-dfoztm723u.pdf

A computational study of exact knapsack separation for the generalized assignment problem

The Capacitated Facility Location Problem (CFLP) consists of locating a set of facilities with capacity constraints to satisfy the demands of a set of clients at the minimum cost In this paper we propose a simple and effective heuristic for large-scale instances of CFLP The heuristic is based on a Lagrangean relaxation which is used to select a subset of "promising" variables forming the core problem and on a Branch-and-Cut algorithm that solves the core problem Computational results on very large scale instances (up to 4 million variables) are reported

/pdf/an-effective-heuristic-for-large-scale-capacitated-facility-3mfr9ircuq.pdf

Maurizio Boccia

Papers

Solving a fuel delivery problem by heuristic and exact approaches

A metaheuristic for a two echelon location-routing problem

An aggregation heuristic for large scale p-median problem

A computational study of exact knapsack separation for the generalized assignment problem

An effective heuristic for large-scale capacitated facility location problems