A Decision Support System for Vessel Fleet Analysis for Maintenance Operations at Offshore Wind Farms

This paper presents a decision support system (DSS) for determining the optimal fleet of vessels and helicopters to support maintenance operations at offshore wind farms. This vessel fleet is used to transport maintenance technicians and spare parts to and from the wind farm, and to execute lifts of heavy parts onto the turbines. The cost of the vessel fleet constitutes a major part of the maintenance cost for an offshore wind farm and hence having a cost efficient fleet is essential to reduce the cost of energy. The DSS uses a stochastic optimization model to solve the vessel fleet size and mix problem, and returns the optimal fleet of vessels and other relevant problem output to the decision maker. To test the performance of the DSS, a computational study in three parts is conducted. First, we perform a verification of the underlying mathematical model by comparing results to leading work from the literature, before conducting both in-sample and out-of-sample stability testing to verify that our stochastic modelling approach give stable results that capture the uncertainty of the problem. Finally, we demonstrate how the DSS can help offshore wind farm operators and vessel developers to improve their decision making.