We consider the problem of minimizing the sum of completion times in a two-machine permutation flowshop subject to release dates. We develop several lower bounds and we describe constructive heuristics as well as an effective genetic local search algorithm. Computational experiments carried out...

The two-machine flowshop environment with sequence-independent setup times has been intensely investigated both from theoretical and practical perspectives in the scheduling literature. Nevertheless, very scant attention has been devoted to deriving effective lower bounding strategies. In this...