Supervisors info:
Ιωάννης Εμίρης, καθηγητής, τμήμα Πληροφορικής και Τηλ/νιών, ΕΚΠΑ
Summary:
This thesis aims to find optimal routes, with data given by an oil transfer company, in
order to minimize number of kilometres and, in general, minimize total cost of fuel transfer
from central fuel depot in Athens, to gas stations in Central and Southern Greece and
some islands as well. For the implementation we used Google’s or-tools library which is a
library focused on operations research and provides constraint and routing solvers which
we utilized to achieve our goal. Our next step was to model the problem and its constraints
with or-tools. Indicative constraints are the time windows when gas stations are able to
receive fuels, a few safety constraints such as that the first compartment of each vehicle
has to be filled at least 90% of its volume, and the fact that large compartments have to be
filled more than 80% or less than 20% of their volume. There are 6 different vehicle types,
depending on the size and the ability to carry a tractor. The available veihicles have to be
routed in such a way, that all constraints are met and the transfer cost, which is affected
by the number of kilometres and stops, is minimum. The solution found by our application,
is better and faster than those that humans found by hand.
