This paper presents the performance study of a Genetic Algorithm, for the special case of a mixed model non-permutation flowshop production line, where resequencing is permitted when stations have access to intermittent or centralized resequencing buffers. The access to the buffers is restricted by the number of available buffer places and the physical size of the products. Results from other authors are compared which presented results on permutation sequences [1] or which treat a problem similar to the one studied in this work [2], based on the benchmark data provided by Taillard [3]. Improvements that come with the introduction of constrained resequencing buffers are highlighted.