Dear scheduling researcher, We are delighted to announce the talk given by Martin Skutella (TU Berlin). The title is "Efficient Algorithms and Provably Good Solutions for NP-hard Scheduling Problems". The seminar will take place on Zoom on Wednesday, May 12 at 13:00 UTC: https://cesnet.zoom.us/j/97275617228?pwd=R3ZEMlhialpFSlBUcUo2NEVmS214dz09 <https://cesnet.zoom.us/j/97275617228?pwd=R3ZEMlhialpFSlBUcUo2NEVmS214dz09> Meeting ID: 972 7561 7228 Passcode: 672344 You can follow the seminar online or offline on our Youtube channel as well: https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A The abstract follows. Machine scheduling problems are among the first optimization problems for which approximation algorithms have been analyzed. An approximation algorithm is a polynomial-time algorithm which always finds a feasible solution whose objective function value is within an a priori known factor (performance ratio) of the optimum solution value. In this talk we focus on identical parallel machine scheduling with total weighted completion time objective. We present, among other things, a refined analysis of the performance ratio for the weighted shortest processing time first (WSPT) rule. This is joint work with Sven Jäger. The next seminar in our series will be given by Erik Demeulemeester (FEB-KBI, KU Leuven) "On the State of the Art in Proactive/Reactive Project Scheduling" and it will be held on May 26 at 13:00 UTC. For more details please visit https://schedulingseminar.com/ With kind regards Zdenek, Mike and Guohua