Location-Routing

These are some random instances for the Location-Routing problem (LRP). For a detailed description of the problem and of the used notation, please refer to: D. Ambrosino and M.G. Scutellà "Distribution network design: new problems and related model", European Journal of Operational Research 165(3), pp. 610-624, 2005.

The instances, of increasing size, differ for the number of potential facilities to locate (#CD and #TP), for the number of clients to serve (#BC and #C), and for the cardinality of the fleet (#V). Given the number of clients (C) and big clients (BC) (ranging from 25 to 100 and from 5 to 30, respectively), given the number of potential CD and TP (ranging from 2 to 5 and from 5 to 20, respectively), and given the cardinality of the fleet, the demand of the clients (C and BC) and the capacity of CD and TP have been randomly generated as follows.

The demand of the clients is generated in the interval [1,33], while the demand of the big clients is generated in the interval (33,54]. Moreover, the capacity of each TP is no greater than 110, while the capacity of each CD is generated in an interval [500,b], where b depends on the global demand of C and BC. In particular, the capacities of the CD are generated in such a way to guarantee the existence of a feasible solution.
The distance from BC to the facilities is randomly generated in an interval [1,d], where d can be 250,500,750 and 1000. The distance from the central plant to the CD is randomly generated in an interval [50,d2] where d2 depends on the value assumed by d.
The assignment cost of the clients C to the facilities TP and CD is randomly generated in the interval [4000,50000].

The instances are all contained in LR.tgz (57K); please refer to the provided file CONTENTS.txt for further details.