A tight lower bound for makespan minimization sequence dependent flowshop group scheduling problems

In this paper a lower bounding method for the flowshop sequence dependent groups scheduling problems by minimization of makespan criterion (Fm|fmls, Sijk, prmu|Cmax) is proposed. The performance of the proposed lower bound (LB) is compared with the available lower bounding methods in literature. In order to do this, the performance of the proposed LB and the one available in literature are compared with the available upper bound in literature based on solving the available test problems. The results show that the proposed LB has a superior performance compared to the available ones in literature. The average percentage error of the proposed LB for the test problems is 1.1% and 1.4% for three and six machine problems, respectively.