We investigate the problem of on-line scheduling jobs on m identical parallel machines where preemption is allowed. The goal is to minimize the makespan. We derive an approximation algorithm with worst case guarantee mm/(mm−(m−1)m) for every m≥2, which increasingly tends to e/(e−1)≈1.58 as m→∞. Moreover, we prove that for no m≥2 there does exist any approximation algorithm with a better worst case guarantee.

Additional Metadata
Persistent URL dx.doi.org/10.1016/0167-6377(95)00039-9, hdl.handle.net/1765/100284
Series Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Citation
Chen, B, van Vliet, A, & Woeginger, G.J. (1994). An optimal algorithm for preemptive on-line scheduling. In Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). doi:10.1016/0167-6377(95)00039-9