Branch-and-price algorithm

Abstract

In this chapter we aim at handling problems observed in chapters 2 and 3. When we tackle RRT problems with standard B&B methods we suffer from four main obstacles so far: The problem size is determined by more than n(n - 1) 2 variables and more than 3n(n-1)/2 constraints and allows exact solution only for rather small instances Solutions to LP relaxations in general are highly fractional and provide poor lower bounds When setting variables to integer values in a B&B framework we often experience fractional values coming up for other variables due to model inherent symmetry Cost oriented node order strategies are difficult to implement since fixing variables has intractable consequences for other variables due to the compact structure of time constrained SLS problems © 2008 Springer-Verlag Berlin Heidelberg.