A MILP model for planning the trips of dynamic positioned tankers with variable travel time

• A MILP model for oil tanker scheduling with ship routing and inventory control.
• Arc-based graph model accounting for variable travel time of shuttle tankers.
• A MILP dynamic models for inventory control of transport and production vessels.
• A decision-support tool for planning offloading operations in offshore oil platforms.
• Rolling-horizon and relax-and-fix heuristics for large scheduling instances.

The transportation of the crude oil produced in offshore oilfields to onshore terminals is performed by vessels, known as shuttle tankers. Scheduling shuttle-tanker operations entails solving complex problems to ensure a timely offloading of the platforms, taking into account several logistics and inventory constraints. This work proposes a new MILP formulation that advances previous works by considering variable travel time between platforms and terminals. The combination of the MILP formulation with an optimization solver constitutes a decision-support tool to aid engineers reach optimal decisions for a planning horizon. To handle large-scale instances, rolling-horizon and relax-and-fix strategies are proposed.