Routing of Supply Vessels to with Deliveries and Pickups of Multiple Commodities

This paper considers a single vehicle routing problem with pickups and deliveries of multiple commodities where each customer requires both pickup and delivery of several types of goods from a single depot. This problem arises in offshore upstream logistics and is relevant for the oil and gas companies operating offshore. Offshore installations need to be supplied with several types of goods from an onshore base, and also some cargo need to be transported from the installations back to the base. Supply operations from and to the base are performed by supply vessels, which have separate compartments for different types of cargo. In this paper we present a mathematical formulation for the problem and describe a metaheuristic algorithm yielding non- Hamiltonian routes where customers may be visited once or twice. Computational tests show that the algorithm outperforms CPLEX optimization solver in speed on instances of medium size and generates high quality solutions for large-size instances compared to the Unified Tabu Search algorithm