According to the stress-strain concept of ergonomics, a distinction must be made between the stress on the working human and the resulting individual strain. Furthermore, it must be taken into account whether several influences act simultaneously or one of them acts successively. Therefore, point in time-related and period-related influences are to be considered, whereby in the latter case a connection to discrete event-driven simulation is necessary. It has been known for many years that simulation methods can be used to analyze stress on the human caused by the work task itself, at least in macro-ergonomic terms with regard to time utilization. In addition, anthropometric and work-physiological aspects of the work task can be analyzed using digital human models. The evaluation and assessment of influences from the indoor working environment are more difficult. In this case, both micro- and macro-ergonomic analyzes can be performed. In the following, it is explained in more detail to what extent such forecasts can already be carried out in Digital Factory tools. The result shows that there are still a lot of research and development tasks to be solved before a comprehensive forecast of ergonomic influences can be carried out.