An analysis of decision-making process of shipowners for implementing energy efficiency measures on existing ships: The case of Turkish maritime industry.

Many technical and operational measures provide energy efficiency for existing ships. The decision-making process is very complex as shipowners must consider many criteria regarding the implementation of these measures. This study aims to determine the criteria that shipowners consider while they select energy efficiency measures for existing ships, and the importance levels of these criteria based on shipowners' opinions. Besides, this study aims to determine which energy efficiency measures are preferred more according to the criteria that shipowners consider when they select energy efficiency measures. The questionnaire surveys were conducted face-to-face with twenty-three participants who were senior managers and/or inspectors of shipowner companies in Turkey, and each participant represents one company. The importance levels of the criteria that affect the decision-making process were determined by using the Fuzzy AHP (Analytical Hierarchy Process) method based on obtained quantitative data. The performance values of energy efficiency measures were determined by using the fuzzy TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method. According to the findings, the most important criterion was "Practicality Level of Planning, Procurement and Installation Process". The energy efficiency measure with the highest performance value was "Hull Cleaning". It was seen that the most preferred energy efficiency measures were operational measures instead of retrofit and technical measures. • A framework for decision-making process of Shipowners for Implementing Energy Efficiency Measures is presented. • A combination of Fuzzy AHP and Fuzzy TOPSIS methods is used to determine results of decision-making problem. • The most preferred energy efficiency measures for existing ships are operational instead of retrofits. [ABSTRACT FROM AUTHOR]