NAVAL RESEARCH LOGISTICS, cilt.63, ss.346-348, 2016 (SCI İndekslerine Giren Dergi)
For the single-machine scheduling problem with the objective of simultaneously minimizing total flowtime and number of tardy jobs, a lower bound on the number of efficient sequences is known. However, the proof thereof, which makes use of a modified version of Smith's algorithm, is unduly lengthy and sophisticated. Adopting a totally new point of view, we present in this short article a much simpler proof based on the naive idea of pairwise interchange.