The Probabilistic Traveling Salesman Problem (PTSP) is a TSP problem
where each customer has a given probability of requiring a visit. The
goal is to find an a-priori tour of minimal expected length over all
customers, with the strategy of visiting a random subset of customers in
the same order as they appear in the a-priori tour. The PTSP may be seen
as a "simple" version of a vehicle routing problem with stochastic
demands, where there is one vehicle and where the demand may either zero
(the customer does not require a visit) or one (the customer requires a
visit). An important question about this problem is whether and in which
context an a-priori tour found by a TSP heuristic can also be a good
solution for the PTSP. We investigate this issue by experimentally
testing the relative performance of two ant colony optimization
algorithms, Ant Colony System (ACS) which is a TSP heuristic, and a
variant of it (pACS) that aims to minimize the PTSP objective
function.
Keywords
traveling salesman problem, stochastic optimization problems,
ant colony optimization.
References
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M. Gendreau, G. Laporte, and R. Séguin. (1996)
Stochastic Vehicle Routing,
European Journal of Operation Research, 88:3-12.
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Further results on the probabilistic traveling salesman problem,
European Journal of Operation Research, 65:68-95.