During the development and improvement of multistep batch processes, the description and optimum design of the material and temporal link-up of the various units for reaction, isolation, and solvent work-up is becoming increasingly demanding and requires software support, Distinguishing criteria are first derived for the various simulation tools and these are then supplemented with specific industrial demands placed on simulation tools for overall processes. The authors then provide an overview of commercially available programs above all for simulation of overall processes and report on their own experience. The potential of tools for simulation of overall processes lies not in the reduction of the number of experiments but in better utilisation of plant capacity by improved batch planning, in centralised data storage, in a largely standardised, simplified and consistent documentation, and hence simplified communication.