Variable Neighborhood Search.

Variable neighborhood search: Principles and applications

http://www3.eng.cam.ac.uk/~hj231/Papers/rostering.pdf

Staff scheduling and rostering: A review of applications, methods and models

https://web.stanford.edu/class/msande312/restricted/klos04facility.pdf

Facility location models for distribution system design

In pickup and delivery problems vehicles have to transport loads from origins to destinations without transshipment at intermediate locations. In this paper, we discuss several characteristics that distinguish them from standard vehicle routing problems and present a survey of the problem types and solution methods found in the literature.

/pdf/the-general-pickup-and-delivery-problem-20022i8cyz.pdf

The General Pickup and Delivery Problem

Abstract Column generation is often used to solve large-scale optimization problems, and much research has been devoted to improve the convergence of the solution process. We focus on Kelley's algorithm, which frequently exhibits slow convergence, and propose an algorithm that stabilizes and accelerates the solution process while remaining within the linear programming framework. Preliminary numerical results, obtained on air transportation and location problems, show that the stabilized algorithm can be used to improve the solution times for difficult instances and to solve larger ones.

Stabilized Column Generation

http://solab.kaist.ac.kr/files/IP/IP2013/stabilized.pdf

Stabilized column generation

Time constrained routing and scheduling is of significant importance across land, air and water transportation. These problems are also encountered in a variety of manufacturing, warehousing and service sector environments. Their mathematical complexity and the magnitude of the potential cost savings to be achieved by utilizing O.R. methodologies have attracted researchers since the early days of the field. Witness to this are the pioneering efforts of Dantzig and Fulkerson (1954), Ford and Fulkerson (1962), Appelgren (1969, 1971), Levin (1971), Madsen (1976) and Orloff (1976). Much of the methodology developed has made extensive use of network models and algorithms.

A Unified Framework for Deterministic Time Constrained Vehicle Routing and Crew Scheduling Problems

This paper examines whether there is a substantial additional payoff to be derived from using mathematical optimization techniques to globally define a set of mini-clusters. Specifically, we present a new approximate method to mini-clustering that involves solving a multi-vehicle pick-up and delivery problem with time windows by column generation. To solve this problem we have enhanced an existing optimal algorithm in several ways. First, we present an original network design based on lists of neighboring transportation requests. Second, we have developed a specialized initialization procedure which reduces the processing time by nearly 40%. Third, the algorithm was easily generalized to multi-dimensional capacity. Finally, we have also developed a heuristic to reduce the size of the network, while incurring only small losses in solution quality. This allows the application of our approach to much larger problems. To be able to compare the results of optimization-based and local heuristic mini-clustering,...

Daniel Villeneuve

Papers

Stabilized Column Generation

Stabilized column generation

A Unified Framework for Deterministic Time Constrained Vehicle Routing and Crew Scheduling Problems

A Request Clustering Algorithm for Door-to-Door Handicapped Transportation

Dynamic Aggregation of Set Partitioning Constraints in Column Generation