A method to find the unique optimal fuzzy value of fully fuzzy linear programming problems with inequality constraints having unrestricted L-R fuzzy parameters and decision variables.

•A new lexicographic method to find unique optimal values of FFLP problems is proposed.•Fuzzy inequality relations in the constraint set are defined lexicographically.•Existing lexicographic criteria for ranking L-R fuzzy numbers are easily incorporated.•An application example is given to illustrate the proposed method.•Obtained solutions have better objective values as compared to existing methods.