TY - BOOK

T1 - Approximability and nonapproximability results for minimizing total flow time on a single machine

AU - Kellerer, H.

AU - Tautenhahn, T.

AU - Woeginger, G.J.

PY - 1995

Y1 - 1995

N2 - We consider the problem of scheduling n jobs that are released over time on a single machine in order to minimize the total ??flow time??. This problem is well-??known to be NP??-complete, and the best polynomial time approximation algorithms constructed so far had (more or less trivial)?? worst-??case performance guarantees of O??(n).????
In this paper, we present one positive and one negative result on polynomial time approximations for the minimum total ??flow time problem??. The positive result is the first approxima??tion algorithm with a sublinear worst-??case performance guarantee of O(\sqrt{n}). This algorithm is based on resolving the preemptions of the corresponding optimum preemptive schedule??. The performance guarantee of our approximation algorithm is not far from best possible as our second, negative result demonstrates.?? Unless P=NP, no polynomial time approxima??tion algorithm for minimum total ??flow time can have a worst-??case performance guarantee of O(n^{1/2 - \epsilon}) for any \epsilon > 0.
?? ?? ????
Keywords:?? scheduling, approximation algorithm, worst-??case analysis, total flow time, release time, single machine??.

AB - We consider the problem of scheduling n jobs that are released over time on a single machine in order to minimize the total ??flow time??. This problem is well-??known to be NP??-complete, and the best polynomial time approximation algorithms constructed so far had (more or less trivial)?? worst-??case performance guarantees of O??(n).????
In this paper, we present one positive and one negative result on polynomial time approximations for the minimum total ??flow time problem??. The positive result is the first approxima??tion algorithm with a sublinear worst-??case performance guarantee of O(\sqrt{n}). This algorithm is based on resolving the preemptions of the corresponding optimum preemptive schedule??. The performance guarantee of our approximation algorithm is not far from best possible as our second, negative result demonstrates.?? Unless P=NP, no polynomial time approxima??tion algorithm for minimum total ??flow time can have a worst-??case performance guarantee of O(n^{1/2 - \epsilon}) for any \epsilon > 0.
?? ?? ????
Keywords:?? scheduling, approximation algorithm, worst-??case analysis, total flow time, release time, single machine??.

M3 - Report

T3 - Memorandum COSOR

BT - Approximability and nonapproximability results for minimizing total flow time on a single machine

PB - Technische Universiteit Eindhoven

CY - Eindhoven

ER -