Group decision making problem with different preference structures of DMs

There is so long that group decision making has been emphasized by wise men, as it mentioned in the Persian proverb "move together, die alone." Because of managers always are facing to the conditions that they must consider to other’s point of view the group decision making is clearly general. In real life, the actual challenges are often too complicated that we need variety knowledge in different fields, and no manager has enough qualifications. Group decision making has some advantages like: Increased qualification of decisions, innovation and creativity in the decisions, that will increase adopt of the decisions to people who should perform them. In the paper, we have tried to explain the approaches that experts use to mention their view. Also, we have tried to describe the aggregation of input information with mathematical functions by taking some examples to enhancing the authority of decision makers in presenting his/her points of views, we have added a new input variable that’s the Boolean variable. Then we consider that how does it transform to fuzzy preference relations, and we use it in a practical example. Finally, to approach the stage of the best alternative choices presented by the experts, and reaching the best solution agreed by the body, we used the methods of classical mathematic and fuzzy rules, and prepared the views of experts that presented according to the different preference structures and integrated them to the final process and consensus, and the final appointment