We report on experiments with turning the branch-price-andcut framework SCIP into a generic branch-price-and-cut solver. That is, given a mixed integer program (MIP), our code performs a DantzigWolfe decomposition according to the user’s specification, and solves the resulting re-formulation via branch-and-price. We take care of the column generation subproblems which are solved as MIPs themsel...

Kidney exchange is a barter market where patients trade willing but medically incompatible donors. These trades occur via cycles, where each patient-donor pair both gives and receives a kidney, and via chains, which begin with an altruistic donor who does not require a kidney in return. For logistical reasons, the maximum length of a cycle is typically limited to a small constant, while chains ...

The pharmacy service requires that some pharmacies are always available and shifts have to be organized: a shift corresponds to a subset of pharmacies that must be open 24 hours a day on a particular week. Under the requirement that each pharmacy belongs to exactly one shift and the assumption that users minimize the distance to the closest open pharmacy during each shift, we want to determine ...

In this research, a permutation flowshop sequence-dependent group scheduling problem with minimization of total completion time i.e., is considered. Since the problem is shown to be strongly NP-hard, a hybrid genetic (HG) algorithm is proposed. The only available lower bounding (LB) method for the proposed research problem in the literature based on Branch and Price (B&P) algorithm is also enha...

Combinatorial optimisation problems are easy to state but hard to solve, and they arise in a huge variety of applications. Branch-and-price is one of many powerful methods for solving them. This paper describes how Dantzig-Wolfe decomposition, column generation and branch-and-price are integrated into the hybrid optimisation platform G12 [13]. The G12 project is developing a software environmen...

Twente. Beta is the largest research centre in the Netherlands in the field of operations management in technology-intensive environments. The mission of Beta is to carry out fundamental and applied research on the analysis, design, and control of operational processes. Cover: branching of the Ohio river (satellite image) No part of this work may be reproduced by print, photocopy, or any other ...

The Vehicle Routing Problem with Probabilistic Customers (VRP-PC) is a fundamental building block within the broad family of a priori routing models and has two decision stages. In the first stage, the dispatcher determines a set of vehicle routes serving all potential customer locations before the actual requests for service realize. In the second stage, vehicles are dispatched after observing...

In recent years, considerable effort in the field of operations research has been paid to optimizing airline operations, including the logistics of an airline’s fleet of aircraft. We focus on the problem of aircraft routing, which involves generating and selecting a particular route for each aircraft of a sub-fleet that is already assigned to a set of feasible sequences of flight legs. Similar ...

Sports league scheduling is a hard combinatorial optimization problem. There is a vast field of requests arising in real world problems, e.g., organizational, attractiveness and fairness constraints. A single round robin tournament (SRRT) can be described as a league of a set T of n teams (n even) to be scheduled such that each team plays exactly once against each other team and such that each ...