Three polynomial heuristics with performance guarantees are
available for location-routing problems, but with uncapacitated
depots. Glicksman and Penn (2008) study the group location-routing
problem, in which depots and vehicles have no capacities and
the customers are partitioned into groups. One has to simultaneously
select a subset of depots to be opened and a collection of
tours that covers all customer groups in order to minimize the
costs of the tours and the fixed costs of opened depots. In the related
generalized VRP there is a single depot, each customer group
has its own demand and vehicles are capacitated. A heuristic with
U ð2 1=ðn 1ÞÞ approximation is developed, where U is the cardinality
of the largest group.