Abstract The purpose of this paper is to present a branch-and-price method to
solve a maritime pickup and delivery problem with time windows, cargo coupling,
and synchronized deliveries. This problem originates from a segment of shipping
called project shipping that subsists on transporting unique and specialized cargoes.
The fleet of ships is heterogeneous and considered fixed. Some sets of cargoes are
coupled, meaning that either all or none of them are transported. Further, some of
these coupled cargoes require synchronized deliveries, restricting the time elapsed
between the first and last delivery is made. The objective is to design a route and
schedule for each ship that maximizes the total profit from transporting a subset of
the cargoes available. A new mathematical formulation is presented and solved
using branch-and-price. The subproblem is a new variant of the elementary shortest
path problem with resource constraints, and is solved by dynamic programming.
Finally, the computational results show that the approach presented in this paper is
significantly better than existing methods for solving this problem.