Group Decis Negot DOI 10.1007/s10726-015-9437-7 Conflicting Bifuzzy Multi-attribute Group Decision Making Model with Application to Flood Control Project Che Mohd Imran Che Taib 1 · Binyamin Yusoff 1 · Mohd Lazim Abdullah 1 · Abdul Fatah Wahab 1 © Springer Science+Business Media Dordrecht 2015 Abstract We propose a group decision making model based on conflicting bifuzzy sets (CBFS) where evaluation are bi-valued in accordance to the subjective assessment obtained from the experts for the positive and negative views. This paper discusses the weighting methods for particular attribute and subattribute with emphasis given to the unification of subjective and objective weights. The integration of CBFS in the model is naturally done by extending the fuzzy evaluation in parallel with the intuitionistic fuzzy. We introduce a new technique to compute the similarity measure, being the degree of agreement between the experts. We end up the paper by demonstrating the applicability of the proposed model to the empirical case of flood control project, one of the project selection problems. Keywords Multi-attribute group decision making · Conflicting bifuzzy sets · Similarity measure · Fuzzy TOPSIS · Fuzzy AHP We are grateful for the comments from an anonymous referee. B Che Mohd Imran Che Taib imran@umt.edu.my Binyamin Yusoff binyamin@umt.edu.my Mohd Lazim Abdullah lazim_m@umt.edu.my Abdul Fatah Wahab fatah@umt.edu.my 1 School of Informatics and Applied Mathematics, University Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia 123