Multi-criteria decision-making for marine propulsion: Hybrid, diesel electric and diesel mechanical systems from cost-environment-risk perspectives

The paper introduces a new decision-making process which is used to compare the performance of a ship with either diesel electric hybrid propulsion or conventional propulsion systems. A case study was carried out to compare the performance of both propulsions from cost, environmental and risk perspectives. This paper also overviews the modern approaches of multi-criteria decision-making and highlights some of their shortcomings in particular the fact that these approaches often rely on different criteria such as financial, environmental or risk. This paper aims to overcome this shortcoming by enhancing the process of multi-criteria decision analysis. The key process in this research was to convert all incomparable values into monetary values, thereby enabling the impacts of each criterion to be compared and integrated in a straightforward manner. Results of the case study showed that the use of a hybrid propulsion system could reduce annual operational costs by $ 300,000 (2% total cost) compared with a diesel electric system and almost $ 1 million (7%) compared to a diesel mechanical propulsion system. In order to investigate the optimal use of the hybrid propulsion system, various operational scenarios were identified and applied to the proposed decision-making process. The results showed that operating the ship in hybrid mode during manoeuvring and berthing is more desirable as the holistic cost can reduce in almost $ 1 million. The advantages of the proposed decision making process was illustrated by comparing the results obtained from a conventional decision-making process using the analytical hierarchical method. It is believed that the research findings not only present general understanding of the possible advantages of hybrid propulsion for stakeholders, but provide them with an insight into the enhanced approach into the multi-criteria decision analysis.