The VEBSys modules offer a further option to increase system reliability and to improve service quality. These modules restrict the use of a system to a defined group of users, and create reports about users, usage times, and the system, for simple and convenient quality control and billing. In addition to authorization, VEBSys modules can also be used for control. On the TUnits for supply and disposal for rail coaches, for example, the VEBSys modules control the valves on the supply and disposal hoses, preventing the freshwater from being contaminated by operator error.