Dear scheduling researcher, We are delighted to announce the talk given by Leah Epstein (University of Haifa). The title is "The benefit of preemption". The seminar will take place on Zoom on Wednesday, September 29 at 13:00 UTC. Join Zoom Meeting https://cesnet.zoom.us/j/97989356749?pwd=T2NzMkszN2Y1RDNNZExTc3p0SjJDdz09 <https://cesnet.zoom.us/j/97989356749?pwd=T2NzMkszN2Y1RDNNZExTc3p0SjJDdz09> Meeting ID: 979 8935 6749 Passcode: 307940 You can follow the seminar online or offline on our Youtube channel as well: https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A The abstract follows. Given an input of a scheduling problem, any non-preemptive solution for it can be used as a preemptive solution. Thus, the optimal cost of a preemptive solution is not larger than that of an optimal non-preemptive solution. As preemption comes at a cost in real-life applications, it is of interest to find the worst-case ratio between the two costs. For a given problem, the supremum ratio over all possible inputs of the ratio between the two costs (of an optimal solution without preemption and an optimal solution that possibly uses preemption) is called the power or benefit of preemption. While many scheduling variants can be studied with respect to this measure, we will focus on the cases of a single machine, parallel identical machines, and uniformly related machines, and we will discuss the objectives of makespan and total (weighted) completion time. We will exhibit how one can benefit from preemption, and we will analyze the resulting worst case ratios for several basic models. The next talk in our series will be given by Federico Della Croce (DIGEP - Polito.it) | October 13 | The Longest Processing Time Rule for Identical Parallel Machines Revisited. For more details, please visit https://schedulingseminar.com/ With kind regards Zdenek, Mike and Guohua -- Zdenek Hanzalek Industrial Informatics Department, Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic https://rtime.ciirc.cvut.cz/~hanzalek/