Department of Economics and Management
University of Brescia
SEMINAR
“Offline-Online
Approximate Dynamic Programming
for Dynamic Vehicle Routing
with Stochastic Requests”
Prof. Justin Goodson
Saint Louis University
Missouri.
Chair: Prof. L. Bertazzi
April 11 th, 2016, h. 10.00
Room D2, Brixia building
Although increasing amounts of transaction data make it possible to characterize uncertainties surrounding
customer service requests, few methods integrate predictive tools with prescriptive optimization procedures to
meet growing demand for small-volume urban transport services. We incorporate temporal and spatial
anticipation of service requests into approximate dynamic programming (ADP) procedures to yield dynamic
routing policies for the single-vehicle routing problem with stochastic service requests, an important problem in
city-based logistics. We contribute to the routing literature as well as to the broader field of ADP. We identify
the geographic spread of customer locations as a key predictor of the success of temporal versus spatial
anticipation. We combine value function approximation (VFA) with rollout algorithms as a means of enhancing
the anticipation of the VFA policy, resulting in spatial-temporal rollout policies. Our combination of VFAs and
rollout algorithms demonstrates the potential benefit of using offline and online methods in tandem as a hybrid
ADP procedure, making possible higher-quality policies with reduced computational requirements for real-time
decision-making. Finally, we identify a policy improvement guarantee applicable to VFA-based rollout
algorithms, showing that base policies composed of deterministic decision rules lead to rollout policies with
performance at least as strong as that of the base policy.
Via S. Faustino 74/b, 25122 Brescia – Italy
Tel 00390302988742 Fax 00390302988703
email: [email protected]