Often deviations occur in the execution of a production schedule because prediction of productivity is unrealistic. Therefore, researchers have shown huge interest in understanding and modelling productivity factors to consider them in planning and design of manufacturing systems. In contrast, this paper examines how productivity can be considered in online-scheduling using past and real-time data and which effect this has on the overall system performance. The discrete event simulation exemplarily considering human productivity factors shows promising results but also the need for more complex forecasting methods Future work will also consider other factors such as tool wear and disturbances.