  Motivated by issues dealing with delivery of emergency medical products
during humanitarian disasters, this paper addresses the general problem of
delivering perishable items to remote demands accessible only by helicopters or
drones. Each drone operates out of platforms that may be move when not in use
and each drone has a limited delivery range to service a demand points.
Associated with each demand point is a disutility function, or a cost function,
with respect to time that reflects preferred delivery clock time for the
demanded item, as well as the item's perishability characteristic that models
nonincreasing quality with time. The paper first addresses the problem of
locating the platforms as well concurrently determining which platform serves
which demand points and in what order to minimize total disutility for product
delivery. The second scenario addresses the two-period problem where the
platforms can be relocated, using useable road networks, after the first
period. It can be easily proven that continuous time versions of these problems
are NP-Hard. However, a practical "time-slot" version of the problem, where
time is discretized into slots, can be solved by standard optimization
software. Extensive computational experiments, using different drone delivery
ranges as well as different drone fleet sizes, provide valuable insights on the
performance of such drone delivery systems.
