Because of increased market dynamics, producing companies are forced to position themselves intelligently in the market. In this context, the ability to react quickly, flexible and accurately to the costumers changing demands is very important. In order to achieve this, a firm and precise production planning, - scheduling and - control is required. This involves - among other issues - the planning of lot sizes, which have a severe impact on the flow of materials through the production process. Therefore this thesis tries to explain the main correlations between the chosen batch sizes and the cycle time of one or many job(s) through a work station or production line. Particularly it pays attention to the multiple effects of stochastic processes and their consequences. The theoretical basis of most of the considerations is given by the Queuing Theory and Little's Law. The results of the theoretical examinations are then interpreted with the help of several simple examples as well as validated by many simulation runs using the modeling - software "plant simulation" from technomatrix. The main results are - the exposure of principal interdependencies of the characteristic key data, such as work in progress, utilization, and cycle time - the demonstration of the effects on the material flow of single jobs as well as product- mixes caused by batching decisions - the parametrization of the stochastic arrival - and treatment processes including availability, setup procedures etc. using samples - the identification of the influence of batching on the variability of material flows - a more general formulation of the equations to determine the effect of overlapping - an investigation and discussion of the two approaches to develop the characteristic curves for a production system (Produktions- und Prozesskennlinien) Summing up, this paper examines some key aspects of the flow of materials in a production environment and the multiple impacts of batching decisions.