Geoscience Reference
In-Depth Information
Chapter 15
Location-Routing and Location-Arc Routing
Maria Albareda-Sambola
Abstract
This chapter overviews the most relevant contributions on location-
routing problems. Although there exist many different models where location and
routing decisions must be made in an integrated way, the chapter focuses on the
so-called classical location-routing problems without entering into the details of
other related problems that might be included in the location-routing area from
a more general point of view. Reflecting the imbalance in the existing literature
and available approaches, the case of problems with node routing is treated in
detail throughout the chapter, while results concerning arc routing problems are
concentrated in a single section.
Keywords
Discrete location-routing Heuristics Mathematical programming
15.1
Introduction
Combined location-routing problems (LRPs) are location problems where the
service to customers is provided by a fleet of vehicles in less-than-truckload routes.
That is, more than one customer can be served in one vehicle route from a facility.
Therefore, the cost of servicing a customer in a solution of a location-routing
problem does not only depend on the facility it is assigned to, but also on the
route followed by the vehicle that services it. As happens with pure vehicle routing
problems, a basic distinction needs to be made when referring to LRPs, depending
on whether the customers are associated with nodes or links of the underlying
network. In the first case, in order to provide service to a customer, a vehicle has to
visit the corresponding node, whereas in the second case, the vehicle has to traverse
the corresponding link. Most of the literature on LRPs is in fact devoted to node
routing LRPs and only a few references are concerned with solving some variant
with arc routing. For this reason, the name
location-routing problem
is commonly
used to refer to problems where customers are located at the nodes, whereas the
term
location-arc routing problem
(LARP) is used when customers are located on
