A model proposal to examine the effects of ships to marine pollution in terms of internal and external factors

Marine pollution is an important environmental problem. One of the important causes of marine pollution is ship origin. This study deals with defining the importance degrees of ship origin marine pollution criteria. This paper suggests employing quality function deployment (QFD), interval type-2 fuzzy (IT2F) numbers, TOPSIS (technique for order performance by similarity to ideal solution) and SWOT analysis to determine these importance degrees. Internal factors, which indicate the strengths and weaknesses of the SWOT analysis in this paper, are the infrastructure of the sea to prevent pollution. External factors, which indicate the opportunities and threats of the SWOT analysis in this paper, are ship-related activities that cause pollution of the relevant sea. Five CRs and fourteen DRs are handled to examine ship origin marine pollution. Three experts have presented their judgments about the correlations and relationships of design requirements (DRs) and customer requirements (CRs). The proposed IT2F number-based QFD method uses IT2F numbers to determine the weights of DRs with the help of the correlations and relationships of the DRs and CRs. The most important internal factors are complying with the law and hard supervision, respectively. The most important external factors are direct discharge of waters of tank washing, direct discharge of ballast waters of ships and direct discharge of bilge waters of ships, respectively. Four seas are ranked in terms of ship origin marine pollution by using TOPSIS approach based on IT2F number. The most polluted sea exposed to ship origin marine pollution is Sea of Marmara according to the obtained results.