Selecting technological alternatives for regulatory compliance towards emissions reduction from shipping: An integrated fuzzy multi-criteria decision-making approach under vague environment

Abstract

Due to the increasing pressure from stricter environmental regulations to reduce emissions in shipping, the maritime industry has been striving for finding more effective measures. Existing measures are often not enough to comply with new regulations. Among various alternative measures, it is not easy for decision-makers (shipowners and operators) to choose the most suitable alternative measure as it involves with multi-criteria decision-making where the prioritization of a number of alternatives vis-à-vis multiple criteria evaluation is undertaken. Further challenges on such analysis are the lack of information as well as its subjectivity and/or the inconsistency. This study proposes an integrative fuzzy multi-criteria decision-making method that combines fuzzy analytic hierarchy process (AHP) and fuzzy technique for order performance by similarity to ideal solution (TOPSIS) for the selection of technological alternatives for regulatory compliance under vague environment. Nine criteria within three sustainability aspects (social, economic and environmental aspects) were analysed and evaluated as regards four possible alternatives. The weights of these aspects and criteria were determined by the fuzzy AHP; meanwhile, alternatives were prioritized by the fuzzy TOPSIS. According to the outputs of the proposed decision-making framework, the study revealed that low-sulphur fuels are the best suitable alternative for regulatory compliance. The following alternatives are methanol, scrubbers and liquefied natural gas in order. Sensitivity analysis was conducted to tell us that the proposed framework is robust. This proposed method will be potentially applicable to other fields where decisions are required to make under vague information conditions.

The Compliance Challenges in Emissions Control Regulations to Reduce Air Pollution from Shipping

“…Another barriers when conducting this analysis are the inconsistency and vagueness of information. The fuzzy-based approach which integrated the fuzzy AHP and the fuzzy TOPSIS was proposed by [11] to overcome these problems. The outcomes of this study have noted that Low sulphur fuels would be the most suitable option in near future of regulatory compliance for emissions reduction.…”

“…However, each alternative solution will also exert a social impact [10]. The integration of social factor into the evaluation process has been addressed by several scientific studies [11,12]. These factors (economic, environmental and social) are regarded as three pillars of sustainability [13].…”

“…In addition, those studies have only applied either the fuzzy AHP or TOPSIS technique. The fuzzy integrated MCDM approach proposed by [11] has integrated the fuzzy AHP in combination with the fuzzy TOPSIS for selecting technological alternatives for regulatory compliance towards emission reduction from shipping. Several advantages of this integrated fuzzy MCDM include as follows: (i) the fuzzy AHP technique with the utilization of the fuzzy comparison ratio can be able to deal with the ambiguity in the model by precisely resembling the human thinking; (ii) in the fuzzy TOPSIS technique, the computation process might be programmed easily; human choices are embodied in the logical way; the number of stages remains the same irrespective of the number of factors and it reveals a scalar value that represents simultaneously the most and the least alternatives.…”

Ship emissions reduction using weather ship routing optimisation

“…[2][3][4] Furthermore, other strategies are valuable in terms of mitigating emissions, such as the use of low sulphur fuels, 5 burning alternative fuels such as liquefied natural gas (LNG), 6 the use of electric auxiliary propulsion during slow speed sailing 7 or the installation of abatement techniques such as scrubbers, inter alia. Bui et al 8 proposed a multi-criteria decision-making method for the selection of technological alternatives for environmental regulatory compliance. Among the strategies to be applied at a later stage than vessel design, Weather Ship Routing (WSR) (defined as the development of an optimum sailing course and speed for ocean voyages 1 based on forecasted sea conditions), 9 is a robust alternative for reducing external and internal costs.…”

Fabrication, characterization, and selection using FAHP‐TOPSIS technique of zirconia, titanium oxide, and marble dust powder filled dental restorative composite materials

“…It offered a serious assessment of existing practices and provided suggestions for prospective work. Bui et al 19 investigated an integrative fuzzy MCDM technique that adds fuzzy AHP and fuzzy TOPSIS to select scientific alternatives for dogmatic obedience in a hazy situation. This planned technique will be potentially relevant to other fields where decisions must be made under ambiguous information conditions.…”