AbstractReducing Greenhouse Gas Emissions from vessels is one of the greatest challenges the maritime industry is currently facing. International Maritime Organization has set the goal of reducing CO2 emissions from international shipping by at least 40% by 2030, compared to 2008. Emissions regulations are also leading to a progressive reduction of ships life span, together with a decrease in economic value. To cope with these challenges, the preferred strategy suggested by IMO for new vessels -Energy Efficiency Design Index- aims at increasing the energy efficiency over time by stimulating innovation and continuous development of technical elements. In this context, ship builders are indirectly led to develop vessels that will be “changeable” in terms of propulsion systems over time. This paper presents a conceptual framework to maritime vessels for propulsion system changeability, which integrates contributions from literature review with the knowledge of design thinking experts and precious insights of maritime industry professionals. The aim of this framework is support the integration of renewable fuel sources for vessel propulsion systems through an extended value approach, while improving propulsion efficiency over time.