Improved bounds for flow shop scheduling

Abstract

We resolve an open question raised by Feige & Scheideler by showing that the best known approximation algorithm for flow shops is essentially tight with respect to the used lower bound on the optimal makespan. We also obtain a nearly tight hardness result for the general version of flow shops, where jobs are not required to be processed on each machine. Similar results hold true when the objective is to minimize the sum of completion times. © 2009 Springer Berlin Heidelberg.