In this paper, we consider the problem of locating discretionary facil
ities on a network. In contrast to previous work in the area, we no lo
nger assume that information on customers' flows along all paths of th
e network is known (in practice such information is rarely available).
Assuming that the fraction of customers that travel from any node to
any adjacent node in the network is available, the problem of locating
the facilities so as to maximize the fraction of customers that pass
by a facility before reaching their destination is formulated as a non
linear Integer Program. It is shown that by employing the theory of co
nstrained Markov Decision Processes this problem cart be reformulated
as a linear Mixed Integer Program. The paper presents some preliminary
computational results for this formulation as well as results for a g
reedy heuristic algorithm.