Article ID: | iaor20071761 |
Country: | Netherlands |
Volume: | 12 |
Issue: | 4 |
Start Page Number: | 386 |
End Page Number: | 393 |
Publication Date: | Dec 2006 |
Journal: | Journal of Combinatorial Optimization |
Authors: | Cheng T.C.E., Yuan J.J., Ng C.T. |
We consider a two-agent scheduling problem on a single machine, where the objective is to minimize the total completion time of the first agent with the restriction that the number of tardy jobs of the second agent cannot exceed a given number. It is reported in the literature that the complexity of this problem is still open. We show in this paper that this problem is NP-hard under high multiplicity encoding and can be solved in pseudo-polynomial time under binary encoding. When the first agent's objective is to minimize the total weighted completion time, we show that the problem is strongly NP-hard even when the number of tardy jobs of the second agent is restricted to be zero.