Maintenance optimization. Maintenance routes. Offshore wind farms; GRASP + Tabu Search; Metaheuristics.
The big challenge for the offshore wind farm industry to become profitable is to reduce the high costs associated with its operation. In this context, maintenance and operation (O&M) costs have a great impact on industry costs, representing on average 25% of the life cycle cost of an offshore system. Thus, one of the most effective strategies to achieve the optimization of O&M is based on the routing of maintenance actions promoted by the displacement of ships. Thus, this article aims to develop a mathematical model, based on classic models in the literature, capable of optimizing the routing of maintenance actions for a fleet of ships in offshore wind farms by minimizing displacement costs, downtime and penalties. In addition, the model considers corrective and preventive maintenance policies, as well as capacity, demand and time parameters. To solve this problem in polynomial time it is necessary to apply approximate algorithms. Of these, the GRASP + Busca Tabu hybrid metaheuristic stands out for being able to visit different neighborhoods from a viable initial solution and return solutions close to the global optimum. Finally, instances inspired by real contexts were applied. For the above, the proposed mathematical model and the developed metaheuristic were able to find the global optimum for validation instances. While for larger instances the algorithm proved to be applicable and robust as it returned consistent values with relatively low standard deviations. The development of this work resulted in a positive economic, social and environmental impact.