Faranak Mahmoudi - Department of Mathematics, University of Mazandaran, Babolsar, Iran.
Seyed Hadi Nasseri - Department of Mathematics, University of Mazandaran, Babolsar, Iran.

Today, human decisions are more than ever based on information. But most of this information is not definitive, and in this situation, logical decision making is very difficult based on this uncertainty. Different methods are used to represent this uncertainty, including the fuzzy numbers. The fuzzy linear programming problem is one of the interesting concepts to be addressed in fuzzy optimization. Fully Fuzzy Linear Programming Problems (FFLP) are issues in which all parameters of the coefficients of the variables in the target functions, the coefficients of the variables in the constraints, the right-hand side of the constraints, and the decision variables in them are fuzzy. In this paper, we show that Definition ۲.۶ which is used by Ezzati et al. [۱], failed to compare any arbitrary triangular fuzzy numbers. We demonstrate that their presented method is not well in general, thus the proposed method finds the fuzzy optimal solution of fully fuzzy linear programming problems by Ezzati et al. [۱]. Then a new approach is proposed for solving this FFLP problem. An example is also presented to demonstrate the new method.

fully fuzzy linear programming, triangular fuzzy numbers, ranking function, Fuzzy number