The data-driven decision support system gives a competitive advantage by the cost-effective improvement of the fleet’s energy efficiency and by the controlled compliance with the IMO Greenhouse Gas Reduction Strategy. The conceptual Business Intelligence Design provides the foundation for data-driven decision support about energy efficiency for the entire Offshore Energy fleet. Boskalis Long Distance Towage department can cost-effectively improve their energy efficiency by 40% toward 2030 with respect to 2008 and thereby fully comply with the outlines of the IMO Greenhouse Gas Reduction Strategy. Boskalis offshore energy is recommanded to implement a Data-driven Decision Support System to manage the cost-effective energy efficiency improvement and the reduction of carbon emission. The organisational awareness and willingness to improve is a prerequisition for successful implementation.