In the oil industry, different oil components are blended in a
refinery to fuel products. These products are transported to different
harbors by ship. Due to the limited storage capacity at the harbors
and the undesirability of a stock-out, inventory levels at the
harbors have to be taken into account during the construction of the
ship routes. In this paper, we give a detailed description of this
problem, which we call the ship routing problem with multiple
products and inventory constraints. Furthermore, we formulate this
problem as a generalized set-covering problem, and we present a
Branch-and-Price algorithm to solve it. The pricing problems have a
very complex nature. We discuss a dynamic programming algorithm to
solve them to optimality
