There's a detailed description of the batch mode in the FEFLOW help system: Open help, go to 'Top' level, and hit the 'Batch mode' button. From FEFLOW 5.4 on, there is a completely graphic-less executable. Using this graphic-less mode can save time, especially compared to a simulation where results of all the time steps are rendered. The advantages compared to a simulation including graphics, but without updating for all time steps are less significant when looking at one single model only. However, the startup time of the graphic-less executable is shorter, so this option has advantages when running large numbers of small and fast-running models, e.g., in parameter estimation or optimization.