Local and global dominance conditions for the weighted earliness scheduling problem with no idle time

In this paper, we present several local and global dominance conditions for the single machine weighted earliness scheduling problem with no idle time. We also propose an improvement algorithm that uses these conditions and can be applied to improve the sequence given by a heuristic procedure. This algorithm can be used to improve not only upper bounds for the weighted earliness criterion, but also lower bounds for the earliness/tardiness scheduling problem. The computational tests show that, in both of these cases, the improvement algorithm is superior to an initial heuristic schedule, as well as an existing adjacency condition.