Journal of Intelligent & Fuzzy Systems 39 (2020) 4557–4576 DOI:10.3233/JIFS-200522 IOS Press 4557 Shipyard location selection based on fuzzy AHP and TOPSIS Abdullah T ¨ urk a, * and Murat ¨ Ozk¨ ok a Department of Naval Architecture and Marine Engineering, Karadeniz Technical University, Trabzon, Turkey Abstract. The shipyard facility location selection (FLS) decision is a critical process that involves conflicting, qualitative, and quantitative criteria. Multi-Attribute Decision Making (MADM) methods are used as a powerful tool to overcome this complex problem. Today, using these methods in an integrated way, more accurate, efficient, and systematic results are obtained in solving complex issues such as FLS, which contains an uncertain structure. This paper proposes a framework for the weighting of criteria and ranking potential feasible locations (alternatives) using the combination of fuzzy analytical hierarchy process (AHP) and fuzzy technique for order performance by similarity to ideal solution (TOPSIS) methods. While fuzzy AHP determines the importance values of the criteria by pairwise comparisons, fuzzy TOPSIS prioritizes the alternatives using the relative weights obtained with Fuzzy AHP. The integration of these two techniques provides a robust approach considering the results obtained for the shipyard FLS decision. The applicability of the proposed method is expressed in Turkey by a case study of the shipyard FLS decision. Keywords: Shipyard, location selection, fuzzy AHP, fuzzy TOPSIS 1. Introduction The concept of globalization has emerged with the advances in technique. The new world order brought by this concept has caused the competition of firms to increase with their rivals in their own country and other countries. This increased competition made it imperative that firms behave more rigorously in all decisions they had to make to survive. Therefore, all decisions should be supported by scientific data and based on a systematic structure. Decision making is a process that has different and non-commensurable standards [1] and should be conducted meticulously in such an era where competition is very high. FLS is considered a significant problem that requires a decision-making process and is defined as ∗ Corresponding author. Abdullah T¨ urk, Assistant, Naval Archi- tecture and Marine Engineering, Karadeniz Technical University, Surmene Faculty of Marine Sciences Camburnu/S¨ urmene, S¨ urmene, 61600, Turkey. Fax: +90 462 377 80 58; E-mail: abdullahturk@ktu.edu.tr. the geographic location where a firm continues its activities [2]. This location should enable the firm to achieve low cost and high-profit rates and reach its goals in the long run. Therefore, a correct FLS deci- sion is a critical process for firms, and an incorrect FLS decision causes inefficient use of raw materials, inadequate transportation, and increased operating costs [3]. FLS can occur due to many factors. The idea of establishing a new facility is the most impor- tant of these factors. The following factors are also considered in the occurrence of FLS: technological innovations, management changes, design changes in the manufactured product or new product designs, shift in demand, economic fluctuations, new machine purchases, adverse effects of environmental problems on the facility, and finally broader capacity needs [4]. Before FLS, a firm determines in which area it will serve and what kind of products it will produce. It then determines the criteria of a geographic loca- tion, defined as all conditions and features required ISSN 1064-1246/20/$35.00 © 2020 – IOS Press and the authors. All rights reserved