Preemptive scheduling in a two-stage multiprocessor flow shop is NP-hard

J Hoogeveen
1996 European Journal of Operational Research  
Johnson [1954] gave an efficient algorithm for minimizing makespan in a two-rnachine flow shop; there is no advantage to preemption in this case. McNaughton's wrap-around Nle [1959] finds a shortest preemptive schedule on identical parallel machines in Unear time. A simi-1ar1y efficient aJgorithm is unlikely to exist for the simplest common generalization of these pr0blems. We show that preemptive scheduling in a two-stage flow shop with at least two identical parallel machines in one of the
more » ... ges so as to minimize makespan is NP-hard in the strong sense. 1991 Mathematics Subject Classification: 90835.
doi:10.1016/0377-2217(94)00235-5 fatcat:2dpe64hanjgavaofqasiwjjamy