In this talk, we study scheduling problems where the duration of activities to be scheduled depends on the time of execution and executed activities consume a resource with limited availability. In the case where battery-powered engines are required by the activities, variations in duration can lead to higher or lower overall energy consumption. Therefore, the timing of activities may determine whether the battery depletes before completing activities or not. Because of the interaction between time-dependent activity duration and resource consumption, scheduling policies based on starting all activities as early as possible may fail due to unnecessarily high resource consumption. We propose a dynamic discretization discovery algorithm, an efficient algorithm based on cumulative consumption functions for the case of piecewise linear duration and consumption functions, and an algorithmic framework for efficiently building and exploring a search tree considering possible replenishments of the resource. We evaluate our approaches on a case of routing a fleet of electric vehicles in which vehicles can recharge batteries en route.
Dr. Steffen Pottel joined Kühne Logistics University in March 2018 as a Research Associate in the field of Logistics and Supply Chain Management. He is the principal investigator of a research project on emission-free urban deliveries that is conducted in collaboration with major partners from the parcel and automotive industry. In this context, Steffen focuses on modeling last-mile delivery problems and designing algorithms for optimizing vehicle routes. He was a PhD candidate at the Faculty for Physics and Earth Sciences, University Leipzig, and was a Fellow of the International Max Planck Research School "Mathematics in the Sciences".