Dear scheduling researcher, We are delighted to announce the talk given by Rachel R. Chen (UC Davis). The title is "Outpatient Appointment Scheduling with Waiting Time Limits". The seminar will take place on Zoom on Wednesday, November 12 at 14:00 UTC. Join Zoom Meeting https://cesnet.zoom.us/j/98020327183?pwd=51usye8bYlWTWomIA9ZVVqiiwmj2ec.1 Meeting ID: 980 2032 7183 Passcode: 076268 You can follow the seminar online or offline on our Youtube channel as well: https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A The abstract follows. This paper studies outpatient appointment scheduling with waiting time limits, in the presence of uncertain service times, patient no-shows and unpunctual arrivals. To tackle the problem of excessively long waiting times, policymakers may impose a waiting time limit. The introduction of waiting time limits increases the complexity of model formulation by significantly increasing the number of problem scenarios. To address this challenge, we introduce the concept of virtual waiting time, representing the additional waiting time that a patient would have to incur to see the doctor beyond the imposed waiting time limit. Using this construct, we are able to unify the modeling of system dynamics of all different scenarios into one stochastic program. We develop a tailored integer L-shaped method to solve this model and test its effectiveness against two benchmarks. Specifically, the subproblem is a mixed integer nonlinear program with good properties, which allow us to deduce its optimal value without using optimization solver. We find that the presence of waiting time limits increases the job allowance between two adjacent patients, and the optimal schedule does not necessarily exhibit the well-known dome-shaped pattern. We also find that waiting time limits help reduce variation in patient waiting times across different positions in the schedule, thereby enhancing fairness in the schedule. Furthermore, our results indicate that in the presence of waiting time limits, the total cost of the system is minimized when patients tend to arrive slightly late on average. Finally, we find that when a social planner sets the limit, the clinic has incentives to misreport its true cost of serving each diverted patient, and an additional fine on top of the time limits helps improve social welfare. The next talk in our series will be: Hoogeveen, J.A. (Utrecht University) | November 26 | Planning shunting operations at railway hubs For more details, please visit https://schedulingseminar.com/ With kind regards Zdenek Hanzalek, Michael Pinedo and Guohua Wan -- 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/