The joint project AQUA-IT-Lab wants to develop new solutions for small and medium-sized operators of critical infrastructures. The safety of existing systems should be investigated with a reasonable effort for the operator. For small operators, a quick test will be developed. For medium-sized operators, a laboratory will set up a test environment with a combination of typical computer, guidance and control systems. Simulation programs allow a detailed examination and detailed safety tests without having to intervene in the ongoing operation of the systems. From the insights gained in this way, adapted, resource-saving and holistic packages of measures for improving IT security at the operators should be derived. The measures cover technical as well as organizational and personnel aspects of risk management. In accordance with the requirements of the operators, the complexity of the measures is adapted to the respective framework conditions.