Abstract: In this study, the triangular membership functions are used for flexible flow-lines with m machine centers to examine processing-time uncertainties and to make scheduling more suitable for real applications. A methodology is developed for modeling flexible flow line scheduling with fuzzy processing times, fuzzy due dates, fuzzy set-up times, fuzzy holding costs and fuzzy shortage costs. A fuzzy scheduling model is presented and a hybrid algorithm is also designed for its solution. Finally, some numerical examples are developed and solved to demonstrate the computational efficiency of the proposed algorithm.